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Kell RM, Subhas AV, Schanke NL, Lees LE, Chmiel RJ, Rao D, Brisbin MMM, Moran DM, McIlvin MR, Bolinesi F, Mangoni O, Casotti R, Balestra C, Horner T, Dunbar RB, Allen AE, DiTullio GR, Saito MA. Zinc stimulation of phytoplankton in a low carbon dioxide, coastal Antarctic environment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.05.565706. [PMID: 37961643 PMCID: PMC10635156 DOI: 10.1101/2023.11.05.565706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Zinc (Zn) is a key micronutrient used by phytoplankton for carbon (C) acquisition, yet there have been few observations of its influence on natural oceanic phytoplankton populations. In this study, we observed Zn limitation of growth in the natural phytoplankton community of Terra Nova Bay, Antarctica, due to low (~220 μatm) pCO2 conditions, in addition to primary iron (Fe) limitation. Shipboard incubation experiments amended with Zn and Fe resulted in significantly higher chlorophyll a content and dissolved inorganic carbon drawdown compared to Fe addition alone. Zn and Fe response proteins detected in incubation and environmental biomass provided independent verification of algal co-stress for these micronutrients. These observations of Zn limitation under low pCO2 conditions demonstrate Zn can influence coastal primary productivity. Yet, as surface ocean pCO2 rises with continued anthropogenic emissions, the occurrence of Zn/C co-limitation will become rarer, impacting the biogeochemical cycling of Zn and other trace metal micronutrients.
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González-Dávila M, Maldonado MT, González AG, Guo J, González-Santana D, Martel A, Santana-Casiano JM. Cu transport and complexation by the marine diatom Phaeodactylum tricornutum: Implications for trace metal complexation kinetics in the surface ocean. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 919:170752. [PMID: 38340864 DOI: 10.1016/j.scitotenv.2024.170752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/30/2024] [Accepted: 02/04/2024] [Indexed: 02/12/2024]
Abstract
Elucidating whether dissolved Cu uptake is kinetically or thermodynamically controlled, and the effects of speciation on Cu transport by phytoplankton will allow better modeling of the fate and impact of dissolved Cu in the ocean. To address these questions, we performed Cu physiological and physicochemical experiments using the model diatom, Phaeodactylum tricornutum, grown in natural North Atlantic seawater (0.44 nM Cu). Using competitive ligand equilibration-cathodic stripping voltammetry (CLE-CSV), we measured two organic ligand types released by P. tricornutum to bind Cu (L1 and L2) at concentrations of ~0.35 nM L1 and 1.3 nM L2. We also established the presence of two putative Cu-binding sites at the cell surface of P. tricornutum (S1 and S2) with log K differing by ~5 orders of magnitude (i.e., 12.9 vs. 8.1) and cell surface densities by 9-fold. Only the high-affinity binding sites, S1, exhibit reductase activity. Using voltammetric kinetic measurements and a theoretical kinetic model, we calculated the forward and dissociation rate constants of L1 and S1. Complementary 67Cu uptake experiments identified a high- and a low-affinity Cu uptake system in P. tricornutum, with half-saturation constant (Km) of 154 nM and 2.63 μM dissolved Cu, respectively. In the P. tricornutum genome, we identified a putative high-affinity Cu transporter (PtCTR49224) and a putative ZIP-like, low-affinity Cu transporter (PtZIP49400). PtCTR49224 has high homology to Homo sapiens hCTR1, which depending on the accessibility to extracellular reducing agents, the hCTR1 itself is involved in the reduction of Cu2+ to Cu+ before internalization. We combined these physiological and physicochemical data to calculate the rate constants for the internalization of Cu, and established that while the high-affinity Cu uptake system (S1) is borderline between a kinetically or thermodynamically controlled system, the low-affinity Cu transporters, S2, is thermodynamically-controlled. We revised the inverse relationship between the concentrations of inorganic complexes of essential metals (i.e., Ni, Fe, Co, Zn, Cd, Mn and Cu) in the mixed layer and the formation rate constant of metal transporters in phytoplankton, highlighting the link between the chemical properties of phytoplankton metal transporters and the availability and speciation of trace metals in the surface ocean.
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Affiliation(s)
- Melchor González-Dávila
- Instituto de Oceanografía y Cambio Global, IOCAG, Universidad de Las Palmas de Gran Canaria, ULPGC, Spain.
| | - Maria T Maldonado
- Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia Vancouver, BC, Canada.
| | - Aridane G González
- Instituto de Oceanografía y Cambio Global, IOCAG, Universidad de Las Palmas de Gran Canaria, ULPGC, Spain.
| | - Jian Guo
- Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia Vancouver, BC, Canada.
| | - David González-Santana
- Instituto de Oceanografía y Cambio Global, IOCAG, Universidad de Las Palmas de Gran Canaria, ULPGC, Spain.
| | - Antera Martel
- Banco Español de Algas, Instituto de Oceanografía y Cambio Global, IOCAG, Universidad de Las Palmas de Gran Canaria, ULPGC, Spain.
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Moreno CM, Bernish M, Meyer MG, Li Z, Waite N, Cohen NR, Schofield O, Marchetti A. Molecular physiology of Antarctic diatom natural assemblages and bloom event reveal insights into strategies contributing to their ecological success. mSystems 2024; 9:e0130623. [PMID: 38411098 PMCID: PMC10949512 DOI: 10.1128/msystems.01306-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 01/30/2024] [Indexed: 02/28/2024] Open
Abstract
The continental shelf of the Western Antarctic Peninsula (WAP) is a highly variable system characterized by strong cross-shelf gradients, rapid regional change, and large blooms of phytoplankton, notably diatoms. Rapid environmental changes coincide with shifts in plankton community composition and productivity, food web dynamics, and biogeochemistry. Despite the progress in identifying important environmental factors influencing plankton community composition in the WAP, the molecular basis for their survival in this oceanic region, as well as variations in species abundance, metabolism, and distribution, remains largely unresolved. Across a gradient of physicochemical parameters, we analyzed the metabolic profiles of phytoplankton as assessed through metatranscriptomic sequencing. Distinct phytoplankton communities and metabolisms closely mirrored the strong gradients in oceanographic parameters that existed from coastal to offshore regions. Diatoms were abundant in coastal, southern regions, where colder and fresher waters were conducive to a bloom of the centric diatom, Actinocyclus. Members of this genus invested heavily in growth and energy production; carbohydrate, amino acid, and nucleotide biosynthesis pathways; and coping with oxidative stress, resulting in uniquely expressed metabolic profiles compared to other diatoms. We observed strong molecular evidence for iron limitation in shelf and slope regions of the WAP, where diatoms in these regions employed iron-starvation induced proteins, a geranylgeranyl reductase, aquaporins, and urease, among other strategies, while limiting the use of iron-containing proteins. The metatranscriptomic survey performed here reveals functional differences in diatom communities and provides further insight into the environmental factors influencing the growth of diatoms and their predicted response to changes in ocean conditions. IMPORTANCE In the Southern Ocean, phytoplankton must cope with harsh environmental conditions such as low light and growth-limiting concentrations of the micronutrient iron. Using metratranscriptomics, we assessed the influence of oceanographic variables on the diversity of the phytoplankton community composition and on the metabolic strategies of diatoms along the Western Antarctic Peninsula, a region undergoing rapid climate change. We found that cross-shelf differences in oceanographic parameters such as temperature and variable nutrient concentrations account for most of the differences in phytoplankton community composition and metabolism. We opportunistically characterized the metabolic underpinnings of a large bloom of the centric diatom Actinocyclus in coastal waters of the WAP. Our results indicate that physicochemical differences from onshore to offshore are stronger than between southern and northern regions of the WAP; however, these trends could change in the future, resulting in poleward shifts in functional differences in diatom communities and phytoplankton blooms.
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Affiliation(s)
- Carly M. Moreno
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Margaret Bernish
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Meredith G. Meyer
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Zuchuan Li
- Division of Natural and Applied Science, Duke Kunshan University, Suzhou, Jiangsu, China
| | - Nicole Waite
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, New Jersey, USA
| | - Natalie R. Cohen
- Skidaway Institute of Oceanography, University of Georgia, Savannah, Georgia, USA
| | - Oscar Schofield
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, New Jersey, USA
| | - Adrian Marchetti
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Berdun F, Valiñas M, Pagnussat G, Zabaleta E. Mobilization of Plasmids From Bacteria Into Diatoms by Conjugation Technique. Bio Protoc 2024; 14:e4945. [PMID: 38464938 PMCID: PMC10917694 DOI: 10.21769/bioprotoc.4945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 12/12/2023] [Accepted: 01/23/2024] [Indexed: 03/12/2024] Open
Abstract
Diatoms serve as a source for a variety of compounds with particular biotechnological interest. Therefore, redirecting the flow to a specific pathway requires the elucidation of the gene's specific function. The most commonly used method in diatoms is biolistic transformation, which is a very expensive and time-consuming method. The use of episomes that are maintained as closed circles at a copy number equivalent to native chromosomes has become a useful genetic system for protein expression that avoids multiple insertions, position-specific effects on expression, and potential knockout of non-targeted genes. These episomes can be introduced from bacteria into diatoms via conjugation. Here, we describe a detailed protocol for gene expression that includes 1) the gateway cloning strategy and 2) the conjugation protocol for the mobilization of plasmids from bacteria to diatoms.
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Affiliation(s)
- Federico Berdun
- Instituto de Investigaciones Biológicas, IIB-CONICET-Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - Matías Valiñas
- Instituto de Investigaciones Biológicas, IIB-CONICET-Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - Gabriela Pagnussat
- Instituto de Investigaciones Biológicas, IIB-CONICET-Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - Eduardo Zabaleta
- Instituto de Investigaciones Biológicas, IIB-CONICET-Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
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Pan Y, Zhang W, Wang X, Jouhet J, Maréchal E, Liu J, Xia XQ, Hu H. Allele-dependent expression and functionality of lipid enzyme phospholipid:diacylglycerol acyltransferase affect diatom carbon storage and growth. PLANT PHYSIOLOGY 2024; 194:1024-1040. [PMID: 37930282 DOI: 10.1093/plphys/kiad581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 09/06/2023] [Accepted: 10/11/2023] [Indexed: 11/07/2023]
Abstract
In the acyl-CoA-independent pathway of triacylglycerol (TAG) synthesis unique to plants, fungi, and algae, TAG formation is catalyzed by the enzyme phospholipid:diacylglycerol acyltransferase (PDAT). The unique PDAT gene of the model diatom Phaeodactylum tricornutum strain CCMP2561 boasts 47 single nucleotide variants within protein coding regions of the alleles. To deepen our understanding of TAG synthesis, we observed the allele-specific expression of PDAT by the analysis of 87 published RNA-sequencing (RNA-seq) data and experimental validation. The transcription of one of the two PDAT alleles, Allele 2, could be specifically induced by decreasing nitrogen concentrations. Overexpression of Allele 2 in P. tricornutum substantially enhanced the accumulation of TAG by 44% to 74% under nutrient stress; however, overexpression of Allele 1 resulted in little increase of TAG accumulation. Interestingly, a more serious growth inhibition was observed in the PDAT Allele 1 overexpression strains compared with Allele 2 counterparts. Heterologous expression in yeast (Saccharomyces cerevisiae) showed that enzymes encoded by PDAT Allele 2 but not Allele 1 had TAG biosynthetic activity, and 7 N-terminal and 3 C-terminal amino acid variants between the 2 allele-encoded proteins substantially affected enzymatic activity. P. tricornutum PDAT, localized in the innermost chloroplast membrane, used monogalactosyldiacylglycerol and phosphatidylcholine as acyl donors as demonstrated by the increase of the 2 lipids in PDAT knockout lines, which indicated a common origin in evolution with green algal PDATs. Our study reveals unequal roles among allele-encoded PDATs in mediating carbon storage and growth in response to nitrogen stress and suggests an unsuspected strategy toward lipid and biomass improvement for biotechnological purposes.
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Affiliation(s)
- Yufang Pan
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Wanting Zhang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Xiaofei Wang
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Juliette Jouhet
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG-LPCV, Grenoble Cedex 9 38054, France
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG-LPCV, Grenoble Cedex 9 38054, France
| | - Jin Liu
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Xiao-Qin Xia
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hanhua Hu
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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Liu X, Zuo Z, Xie X, Gao S, Wu S, Gu W, Wang G. SLC24A-mediated calcium exchange as an indispensable component of the diatom cell density-driven signaling pathway. THE ISME JOURNAL 2024; 18:wrae039. [PMID: 38457651 PMCID: PMC10982851 DOI: 10.1093/ismejo/wrae039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 02/09/2024] [Accepted: 03/04/2024] [Indexed: 03/10/2024]
Abstract
Diatom bloom is characterized by a rapid increase of population density. Perception of population density and physiological responses can significantly influence their survival strategies, subsequently impacting bloom fate. The population density itself can serve as a signal, which is perceived through chemical signals or chlorophyll fluorescence signals triggered by high cell density, and their intracellular signaling mechanisms remain to be elucidated. In this study, we focused on the model diatom, Phaeodactylum tricornutum, and designed an orthogonal experiment involving varying cell densities and light conditions, to stimulate the release of chemical signals and light-induced chlorophyll fluorescence signals. Utilizing RNA-Seq and Weighted Gene Co-expression Network Analysis, we identified four gene clusters displaying density-dependent expression patterns. Within these, a potential hub gene, PtSLC24A, encoding a Na+/Ca2+ exchanger, was identified. Based on molecular genetics, cellular physiology, computational structural biology, and in situ oceanic data, we propose a potential intracellular signaling mechanism related to cell density in marine diatoms using Ca2+: upon sensing population density signals mediated by chemical cues, the membrane-bound PtSLC24A facilitates the efflux of Ca2+ to maintain specific intracellular calcium levels, allowing the transduction of intracellular density signals, subsequently regulating physiological responses, including cell apoptosis, ultimately affecting algal blooms fate. These findings shed light on the calcium-mediated intracellular signaling mechanism of marine diatoms to changing population densities, and enhances our understanding of diatom bloom dynamics and their ecological implications.
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Affiliation(s)
- Xuehua Liu
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, Shandong Province, China
| | - Zhicheng Zuo
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China
- Shanghai Frontiers Science Research Center for Druggability of Cardiovascular Noncoding RNA, Institute for Frontier Medical Technology, Shanghai University of Engineering Science, Shanghai 201620, China
| | - Xiujun Xie
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, Shandong Province, China
| | - Shan Gao
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, Shandong Province, China
| | - Songcui Wu
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, Shandong Province, China
| | - Wenhui Gu
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, Shandong Province, China
| | - Guangce Wang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266404, Shandong Province, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao 266237, Shandong Province, China
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Gao S, Yang W, Li X, Zhou L, Liu X, Wu S, Wang L, Wang G. Cryptochrome PtCPF1 regulates high temperature acclimation of marine diatoms through coordination of iron and phosphorus uptake. THE ISME JOURNAL 2024; 18:wrad019. [PMID: 38365245 PMCID: PMC10837835 DOI: 10.1093/ismejo/wrad019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/02/2023] [Accepted: 12/04/2023] [Indexed: 02/18/2024]
Abstract
Increasing ocean temperatures threaten the productivity and species composition of marine diatoms. High temperature response and regulation are important for the acclimation of marine diatoms to such environments. However, the molecular mechanisms behind their acclimation to high temperature are still largely unknown. In this study, the abundance of PtCPF1 homologs (a member of the cryptochrome-photolyase family in the model diatom Phaeodactylum tricornutum) transcripts in marine phytoplankton is shown to increase with rising temperature based on Tara Oceans datasets. Moreover, the expression of PtCPF1 in P. tricornutum at high temperature (26 °C) was much higher than that at optimum temperature (20 °C). Deletion of PtCPF1 in P. tricornutum disrupted the expression of genes encoding two phytotransferrins (ISIP2A and ISIP1) and two Na+/P co-transporters (PHATRDRAFT_47667 and PHATRDRAFT_40433) at 26 °C. This further impacted the uptake of Fe and P, and eventually caused the arrest of cell division. Gene expression, Fe and P uptake, and cell division were restored by rescue with the native PtCPF1 gene. Furthermore, PtCPF1 interacts with two putative transcription factors (BolA and TF IIA) that potentially regulate the expression of genes encoding phytotransferrins and Na+/P co-transporters. To the best of our knowledge, this is the first study to reveal PtCPF1 as an essential regulator in the acclimation of marine diatoms to high temperature through the coordination of Fe and P uptake. Therefore, these findings help elucidate how marine diatoms acclimate to high temperature.
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Affiliation(s)
- Shan Gao
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266071, China
| | - Wenting Yang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266071, China
| | - Xin Li
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266071, China
- College of Earth Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lu Zhou
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266071, China
| | - Xuehua Liu
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266071, China
| | - Songcui Wu
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266071, China
| | - Lijun Wang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266071, China
| | - Guangce Wang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Qingdao 266071, China
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Russo MT, Rogato A, Jaubert M, Karas BJ, Falciatore A. Phaeodactylum tricornutum: An established model species for diatom molecular research and an emerging chassis for algal synthetic biology. JOURNAL OF PHYCOLOGY 2023; 59:1114-1122. [PMID: 37975560 DOI: 10.1111/jpy.13400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 10/05/2023] [Indexed: 11/19/2023]
Abstract
Diatoms are prominent and highly diverse microalgae in aquatic environments. Compared with other diatom species, Phaeodactylum tricornutum is an "atypical diatom" displaying three different morphotypes and lacking the usual silica shell. Despite being of limited ecological relevance, its ease of growth in the laboratory and well-known physiology, alongside the steady increase in genome-enabled information coupled with effective tools for manipulating gene expression, have meant it has gained increased recognition as a powerful experimental model for molecular research on diatoms. We here present a brief overview of how over the last 25 years P. tricornutum has contributed to the unveiling of fundamental aspects of diatom biology, while also emerging as a new tool for algal process engineering and synthetic biology.
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Affiliation(s)
- Monia T Russo
- Department of Ecosustainable Marine Biotechnology, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Alessandra Rogato
- Institute of Biosciences and Bioresources, National Research Council, IBBR-CNR, Naples, Italy
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Marianne Jaubert
- UMR7141 Laboratoire de Biologie du chloroplaste et perception de la lumière chez les micro-algues, Institut de Biologie Physico-Chimique, Paris, France
| | - Bogumil J Karas
- Department of Biochemistry, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Angela Falciatore
- UMR7141 Laboratoire de Biologie du chloroplaste et perception de la lumière chez les micro-algues, Institut de Biologie Physico-Chimique, Paris, France
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Lampe RH, Coale TH, Forsch KO, Jabre LJ, Kekuewa S, Bertrand EM, Horák A, Oborník M, Rabines AJ, Rowland E, Zheng H, Andersson AJ, Barbeau KA, Allen AE. Short-term acidification promotes diverse iron acquisition and conservation mechanisms in upwelling-associated phytoplankton. Nat Commun 2023; 14:7215. [PMID: 37940668 PMCID: PMC10632500 DOI: 10.1038/s41467-023-42949-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 10/26/2023] [Indexed: 11/10/2023] Open
Abstract
Coastal upwelling regions are among the most productive marine ecosystems but may be threatened by amplified ocean acidification. Increased acidification is hypothesized to reduce iron bioavailability for phytoplankton thereby expanding iron limitation and impacting primary production. Here we show from community to molecular levels that phytoplankton in an upwelling region respond to short-term acidification exposure with iron uptake pathways and strategies that reduce cellular iron demand. A combined physiological and multi-omics approach was applied to trace metal clean incubations that introduced 1200 ppm CO2 for up to four days. Although variable, molecular-level responses indicate a prioritization of iron uptake pathways that are less hindered by acidification and reductions in iron utilization. Growth, nutrient uptake, and community compositions remained largely unaffected suggesting that these mechanisms may confer short-term resistance to acidification; however, we speculate that cellular iron demand is only temporarily satisfied, and longer-term acidification exposure without increased iron inputs may result in increased iron stress.
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Affiliation(s)
- Robert H Lampe
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
- Microbial and Environmental Genomics, J. Craig Venter Institute, 4120 Capricorn Lane, La Jolla, CA, 92037, USA
| | - Tyler H Coale
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
- Microbial and Environmental Genomics, J. Craig Venter Institute, 4120 Capricorn Lane, La Jolla, CA, 92037, USA
| | - Kiefer O Forsch
- Geosciences Research Division, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Loay J Jabre
- Department of Biology and Institute for Comparative Genomics, Dalhousie University, 1355 Oxford St, Halifax, NS, B3H 4R2, Canada
| | - Samuel Kekuewa
- Geosciences Research Division, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Erin M Bertrand
- Department of Biology and Institute for Comparative Genomics, Dalhousie University, 1355 Oxford St, Halifax, NS, B3H 4R2, Canada
| | - Aleš Horák
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, 370 05, České Budějovice, CZ, Czechia
- Faculty of Science, University of South Bohemia, 370 05, České Budějovice, CZ, Czechia
| | - Miroslav Oborník
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, 370 05, České Budějovice, CZ, Czechia
- Faculty of Science, University of South Bohemia, 370 05, České Budějovice, CZ, Czechia
| | - Ariel J Rabines
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
- Microbial and Environmental Genomics, J. Craig Venter Institute, 4120 Capricorn Lane, La Jolla, CA, 92037, USA
| | - Elden Rowland
- Department of Biology and Institute for Comparative Genomics, Dalhousie University, 1355 Oxford St, Halifax, NS, B3H 4R2, Canada
| | - Hong Zheng
- Microbial and Environmental Genomics, J. Craig Venter Institute, 4120 Capricorn Lane, La Jolla, CA, 92037, USA
| | - Andreas J Andersson
- Geosciences Research Division, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Katherine A Barbeau
- Geosciences Research Division, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Andrew E Allen
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA.
- Microbial and Environmental Genomics, J. Craig Venter Institute, 4120 Capricorn Lane, La Jolla, CA, 92037, USA.
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10
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Walworth NG, Espinoza JL, Argyle PA, Hinners J, Levine NM, Doblin MA, Dupont CL, Collins S. Genus-Wide Transcriptional Landscapes Reveal Correlated Gene Networks Underlying Microevolutionary Divergence in Diatoms. Mol Biol Evol 2023; 40:msad218. [PMID: 37874344 PMCID: PMC10595192 DOI: 10.1093/molbev/msad218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 08/24/2023] [Accepted: 09/21/2023] [Indexed: 10/25/2023] Open
Abstract
Marine microbes like diatoms make up the base of marine food webs and drive global nutrient cycles. Despite their key roles in ecology, biogeochemistry, and biotechnology, we have limited empirical data on how forces other than adaptation may drive diatom diversification, especially in the absence of environmental change. One key feature of diatom populations is frequent extreme reductions in population size, which can occur both in situ and ex situ as part of bloom-and-bust growth dynamics. This can drive divergence between closely related lineages, even in the absence of environmental differences. Here, we combine experimental evolution and transcriptome landscapes (t-scapes) to reveal repeated evolutionary divergence within several species of diatoms in a constant environment. We show that most of the transcriptional divergence can be captured on a reduced set of axes, and that repeatable evolution can occur along a single major axis of variation defined by core ortholog expression comprising common metabolic pathways. Previous work has associated specific transcriptional changes in gene networks with environmental factors. Here, we find that these same gene networks diverge in the absence of environmental change, suggesting these pathways may be central in generating phenotypic diversity as a result of both selective and random evolutionary forces. If this is the case, these genes and the functions they encode may represent universal axes of variation. Such axes that capture suites of interacting transcriptional changes during diversification improve our understanding of both global patterns in local adaptation and microdiversity, as well as evolutionary forces shaping algal cultivation.
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Affiliation(s)
- Nathan G Walworth
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089-0371, USA
- J.Craig Venter Institute, La Jolla, CA 92037, USA
| | | | - Phoebe A Argyle
- Climate Change Cluster, University of Technology Sydney, Sydney, New South Wales 2007, Australia
| | - Jana Hinners
- School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
- Helmholtz-Zentrum Hereon, 21502 Geesthacht, Germany
| | - Naomi M Levine
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089-0371, USA
| | - Martina A Doblin
- Climate Change Cluster, University of Technology Sydney, Sydney, New South Wales 2007, Australia
| | | | - Sinéad Collins
- School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
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11
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Li Z, Zhang Y, Li W, Irwin AJ, Finkel ZV. Common environmental stress responses in a model marine diatom. THE NEW PHYTOLOGIST 2023; 240:272-284. [PMID: 37488721 DOI: 10.1111/nph.19147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 06/30/2023] [Indexed: 07/26/2023]
Abstract
Marine planktonic diatoms are among the most important contributors to phytoplankton blooms and marine net primary production. Their ecological success has been attributed to their ability to rapidly respond to changing environmental conditions. Here, we report common molecular mechanisms used by the model marine diatom Thalassiosira pseudonana to respond to 10 diverse environmental stressors using RNA-Seq analysis. We identify a specific subset of 1076 genes that are differentially expressed in response to stressors that induce an imbalance between energy or resource supply and metabolic capacity, which we termed the diatom environmental stress response (d-ESR). The d-ESR is primarily composed of genes that maintain proteome homeostasis and primary metabolism. Photosynthesis is strongly regulated in response to environmental stressors but chloroplast-encoded genes were predominantly upregulated while the nuclear-encoded genes were mostly downregulated in response to low light and high temperature. In aggregate, these results provide insight into the molecular mechanisms used by diatoms to respond to a range of environmental perturbations and the unique role of the chloroplast in managing environmental stress in diatoms. This study facilitates our understanding of the molecular mechanisms underpinning the ecological success of diatoms in the ocean.
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Affiliation(s)
- Zhengke Li
- School of Biological and Pharmaceutical Sciences, Shannxi University of Science and Technology, Xi'an, Shannxi, 710021, China
- Department of Oceanography, Dalhousie University, 1355 Oxford Street, Halifax, NS, B3H 4R2, Canada
| | - Yong Zhang
- Department of Oceanography, Dalhousie University, 1355 Oxford Street, Halifax, NS, B3H 4R2, Canada
- College of Environmental Science and Engineering, Fujian Normal University, Fuzhou, Fujian, 350007, China
| | - Wei Li
- College of Life and Environmental Sciences, Huangshan University, Huangshan, Anhui, 245041, China
| | - Andrew J Irwin
- Department of Mathematics & Statistics, Dalhousie University, 1355 Oxford Street, Halifax, NS, B3H 4R2, Canada
| | - Zoe V Finkel
- Department of Oceanography, Dalhousie University, 1355 Oxford Street, Halifax, NS, B3H 4R2, Canada
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12
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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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13
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Storti M, Hsine H, Uwizeye C, Bastien O, Yee DP, Chevalier F, Decelle J, Giustini C, Béal D, Curien G, Finazzi G, Tolleter D. Tailoring confocal microscopy for real-time analysis of photosynthesis at single-cell resolution. CELL REPORTS METHODS 2023; 3:100568. [PMID: 37751690 PMCID: PMC10545909 DOI: 10.1016/j.crmeth.2023.100568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 02/27/2023] [Accepted: 08/04/2023] [Indexed: 09/28/2023]
Abstract
Photoautotrophs' environmental responses have been extensively studied at the organism and ecosystem level. However, less is known about their photosynthesis at the single-cell level. This information is needed to understand photosynthetic acclimation processes, as light changes as it penetrates cells, layers of cells, or organs. Furthermore, cells within the same tissue may behave differently, being at different developmental/physiological stages. Here, we describe an approach for single-cell and subcellular photophysiology based on the customization of confocal microscopy to assess chlorophyll fluorescence quenching by the saturation pulse method. We exploit this setup to (1) reassess the specialization of photosynthetic activities in developing tissues of non-vascular plants; (2) identify a specific subpopulation of phytoplankton cells in marine photosymbiosis, which consolidate energetic connections with their hosts; and (3) examine the link between light penetration and photoprotection responses inside the different tissues that constitute a plant leaf anatomy.
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Affiliation(s)
- Mattia Storti
- Grenoble Alpes University, CNRS, CEA, INRAE, IRIG-LPCV, 38000 Grenoble, France
| | - Haythem Hsine
- Grenoble Alpes University, CNRS, CEA, INRAE, IRIG-LPCV, 38000 Grenoble, France
| | - Clarisse Uwizeye
- Grenoble Alpes University, CNRS, CEA, INRAE, IRIG-LPCV, 38000 Grenoble, France
| | - Olivier Bastien
- Grenoble Alpes University, CNRS, CEA, INRAE, IRIG-LPCV, 38000 Grenoble, France
| | - Daniel P Yee
- Grenoble Alpes University, CNRS, CEA, INRAE, IRIG-LPCV, 38000 Grenoble, France; Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Fabien Chevalier
- Grenoble Alpes University, CNRS, CEA, INRAE, IRIG-LPCV, 38000 Grenoble, France
| | - Johan Decelle
- Grenoble Alpes University, CNRS, CEA, INRAE, IRIG-LPCV, 38000 Grenoble, France
| | - Cécile Giustini
- Grenoble Alpes University, CNRS, CEA, INRAE, IRIG-LPCV, 38000 Grenoble, France
| | | | - Gilles Curien
- Grenoble Alpes University, CNRS, CEA, INRAE, IRIG-LPCV, 38000 Grenoble, France
| | - Giovanni Finazzi
- Grenoble Alpes University, CNRS, CEA, INRAE, IRIG-LPCV, 38000 Grenoble, France.
| | - Dimitri Tolleter
- Grenoble Alpes University, CNRS, CEA, INRAE, IRIG-LPCV, 38000 Grenoble, France.
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14
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Li J, Zhang K, Li L, Wang Y, Wang C, Lin S. Two-sided effects of the organic phosphorus phytate on a globally important marine coccolithophorid phytoplankton. Microbiol Spectr 2023; 11:e0125523. [PMID: 37702480 PMCID: PMC10655706 DOI: 10.1128/spectrum.01255-23] [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: 03/22/2023] [Accepted: 07/05/2023] [Indexed: 09/14/2023] Open
Abstract
Dissolved organic phosphorus (DOP) is a potential source of aquatic eutrophication and pollution because it can potentially stimulate growth in some species and inhibit growth in other species of algae, the foundation of the marine ecosystem. Inositol hexaphosphate (also named phytic acid or PA), an abundant organophosphate, is presumably ubiquitous in the marine environment, but how it affects marine primary producers is poorly understood. Here, we investigated the bioavailability of this DOP to the cosmopolitan coccolithophore Emiliania huxleyi. Our results showed that E. huxleyi cells can take up PA and dissolved inorganic phosphorus (DIP) simultaneously. Absorbed PA can efficiently support algal growth, producing cell yield between DIP and phosphorus (P)-depleted conditions. Accordingly, PA supply as the sole P source highly influences cellular metabolism and nutrient stoichiometry. Particularly, PA-grown cultures exhibited enhanced carbon fixation, increased lipid content, activated energy metabolism, and induced nitrogen assimilation. However, our data suggest that PA may also exert some levels of toxic effects on E. huxleyi. This study provides novel insights into the variable effects of a DOP on marine phytoplankton, which will inform new inquiries about how the complex DOP constituencies in the ocean will shape phytoplankton community structure and function. IMPORTANCE The dissolved organic phosphorus (DOP) utilization in phytoplankton plays vital roles in cellular P homeostasis, P-nutrient niche, and the dynamics of community structure in marine ecosystems, but its mechanisms, potentially varying with species, are far from clear. In this study, we investigated the utilization of a widespread DOP species, which is commonly produced by plants (land plants and marine macrophytes) and released into coastal areas, in a globally distributed bloom-forming coccolithophore species in various phosphorus environments. Using a combination of physiological and transcriptomic measurements and analyses, our experimental results revealed the complex mechanism and two-sided effects of DOP (major algal growth-supporting and minor toxic effects) in this species, providing a novel perspective on phytoplankton nutrient regulation.
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Affiliation(s)
- Jiashun Li
- Xiamen Key Laboratory of Urban Sea Ecological Conservation and Restoration, State Key Laboratory of Marine Environmental Science, and College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, China
| | - Kaidian Zhang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, Hainan, China
| | - Ling Li
- Xiamen Key Laboratory of Urban Sea Ecological Conservation and Restoration, State Key Laboratory of Marine Environmental Science, and College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, China
| | - Yujie Wang
- Xiamen Key Laboratory of Urban Sea Ecological Conservation and Restoration, State Key Laboratory of Marine Environmental Science, and College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, China
| | - Cong Wang
- Xiamen Key Laboratory of Urban Sea Ecological Conservation and Restoration, State Key Laboratory of Marine Environmental Science, and College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, China
| | - Senjie Lin
- Xiamen Key Laboratory of Urban Sea Ecological Conservation and Restoration, State Key Laboratory of Marine Environmental Science, and College of Ocean and Earth Sciences, Xiamen University, Xiamen, Fujian, China
- Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory of Marine Science and Technology, Qingdao, Shandong, China
- Department of Marine Sciences, University of Connecticut, Groton, Connecticut, USA
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15
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Ban H, Sato S, Yoshikawa S, Yamada K, Nakamura Y, Ichinomiya M, Sato N, Blanc-Mathieu R, Endo H, Kuwata A, Ogata H. Genome analysis of Parmales, the sister group of diatoms, reveals the evolutionary specialization of diatoms from phago-mixotrophs to photoautotrophs. Commun Biol 2023; 6:697. [PMID: 37420035 PMCID: PMC10328945 DOI: 10.1038/s42003-023-05002-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 05/31/2023] [Indexed: 07/09/2023] Open
Abstract
The order Parmales (class Bolidophyceae) is a minor group of pico-sized eukaryotic marine phytoplankton that contains species with cells surrounded by silica plates. Previous studies revealed that Parmales is a member of ochrophytes and sister to diatoms (phylum Bacillariophyta), the most successful phytoplankton group in the modern ocean. Therefore, parmalean genomes can serve as a reference to elucidate both the evolutionary events that differentiated these two lineages and the genomic basis for the ecological success of diatoms vs. the more cryptic lifestyle of parmaleans. Here, we compare the genomes of eight parmaleans and five diatoms to explore their physiological and evolutionary differences. Parmaleans are predicted to be phago-mixotrophs. By contrast, diatoms have lost genes related to phagocytosis, indicating the ecological specialization from phago-mixotrophy to photoautotrophy in their early evolution. Furthermore, diatoms show significant enrichment in gene sets involved in nutrient uptake and metabolism, including iron and silica, in comparison with parmaleans. Overall, our results suggest a strong evolutionary link between the loss of phago-mixotrophy and specialization to a silicified photoautotrophic life stage early in diatom evolution after diverging from the Parmales lineage.
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Affiliation(s)
- Hiroki Ban
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Shinya Sato
- Department of Marine Science and Technology, Fukui Prefectural University, 1-1 Gakuen-cho, Obama City, Fukui, 917-0003, Japan
| | - Shinya Yoshikawa
- Department of Marine Science and Technology, Fukui Prefectural University, 1-1 Gakuen-cho, Obama City, Fukui, 917-0003, Japan
| | - Kazumasa Yamada
- Department of Marine Science and Technology, Fukui Prefectural University, 1-1 Gakuen-cho, Obama City, Fukui, 917-0003, Japan
| | - Yoji Nakamura
- Bioinformatics and Biosciences Division, Fisheries Stock Assessment Center, Fisheries Resources Institute, Japan Fisheries Research and Education Agency, 2-12-4 Fuku-ura, Kanazawa, Yokohama, Kanagawa, 236-8648, Japan
| | - Mutsuo Ichinomiya
- Prefectural University of Kumamoto, 3-1-100 Tsukide, Kumamoto, 862-8502, Japan
| | - Naoki Sato
- Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo, 153-8902, Japan
| | - Romain Blanc-Mathieu
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
- Laboratoire de Physiologie Cellulaire & Végétale, CEA, Univ. Grenoble Alpes, CNRS, INRA, IRIG, Grenoble, France
| | - Hisashi Endo
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
| | - Akira Kuwata
- Shiogama field station, Fisheries Resources Institute, Japan Fisheries Research and Education Agency, 3-27-5 Shinhama-cho, Shiogama, Miyagi, Japan.
| | - Hiroyuki Ogata
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan.
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16
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Inomura K, Pierella Karlusich JJ, Dutkiewicz S, Deutsch C, Harrison PJ, Bowler C. High Growth Rate of Diatoms Explained by Reduced Carbon Requirement and Low Energy Cost of Silica Deposition. Microbiol Spectr 2023; 11:e0331122. [PMID: 37010412 PMCID: PMC10269801 DOI: 10.1128/spectrum.03311-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 03/02/2023] [Indexed: 04/04/2023] Open
Abstract
The rapid growth of diatoms makes them one of the most pervasive and productive types of plankton in the world's ocean, but the physiological basis for their high growth rates remains poorly understood. Here, we evaluate the factors that elevate diatom growth rates, relative to other plankton, using a steady-state metabolic flux model that computes the photosynthetic C source from intracellular light attenuation and the carbon cost of growth from empirical cell C quotas, across a wide range of cell sizes. For both diatoms and other phytoplankton, growth rates decline with increased cell volume, consistent with observations, because the C cost of division increases with size faster than photosynthesis. However, the model predicts overall higher growth rates for diatoms due to reduced C requirements and the low energetic cost of Si deposition. The C savings from the silica frustule are supported by metatranscriptomic data from Tara Oceans, which show that the abundance of transcripts for cytoskeleton components in diatoms is lower than in other phytoplankton. Our results highlight the importance of understanding the origins of phylogenetic differences in cellular C quotas, and suggest that the evolution of silica frustules may play a critical role in the global dominance of marine diatoms. IMPORTANCE This study addresses a longstanding issue regarding diatoms, namely, their fast growth. Diatoms, which broadly are phytoplankton with silica frustules, are the world's most productive microorganisms and dominate in polar and upwelling regions. Their dominance is largely supported by their high growth rate, but the physiological reasoning behind that characteristic has been obscure. In this study, we combine a quantitative model and metatranscriptomic approaches and show that diatoms' low carbon requirements and low energy costs for silica frustule production are the key factors supporting their fast growth. Our study suggests that the effective use of energy-efficient silica as a cellular structure, instead of carbon, enables diatoms to be the most productive organisms in the global ocean.
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Affiliation(s)
- Keisuke Inomura
- Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island, USA
| | - Juan José Pierella Karlusich
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS, INSERM, Université Paris Sciences et Lettres, Paris, France
- Faculty of Arts and Sciences, Division of Science, Harvard University, Cambridge, Massachusetts, USA
| | - Stephanie Dutkiewicz
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Curtis Deutsch
- Department of Geosciences, Princeton University, Princeton, New Jersey, USA
| | - Paul J. Harrison
- Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Chris Bowler
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS, INSERM, Université Paris Sciences et Lettres, Paris, France
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17
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Nymark M, Finazzi G, Volpe C, Serif M, Fonseca DDM, Sharma A, Sanchez N, Sharma AK, Ashcroft F, Kissen R, Winge P, Bones AM. Loss of CpFTSY Reduces Photosynthetic Performance and Affects Insertion of PsaC of PSI in Diatoms. PLANT & CELL PHYSIOLOGY 2023; 64:583-603. [PMID: 36852859 DOI: 10.1093/pcp/pcad014] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 02/17/2023] [Accepted: 02/23/2023] [Indexed: 06/16/2023]
Abstract
The chloroplast signal recognition particle (CpSRP) receptor (CpFTSY) is a component of the CpSRP pathway that post-translationally targets light-harvesting complex proteins (LHCPs) to the thylakoid membranes in plants and green algae containing chloroplasts derived from primary endosymbiosis. In plants, CpFTSY also plays a major role in the co-translational incorporation of chloroplast-encoded subunits of photosynthetic complexes into the thylakoids. This role has not been demonstrated in green algae. So far, its function in organisms with chloroplasts derived from secondary endosymbiotic events has not been elucidated. Here, we report the generation and characterization of mutants lacking CpFTSY in the diatom Phaeodactylum tricornutum. We found that this protein is not involved in inserting LHCPs into thylakoid membranes, indicating that the post-translational part of the CpSRP pathway is not active in this group of microalgae. The lack of CpFTSY caused an increased level of photoprotection, low electron transport rates, inefficient repair of photosystem II (PSII), reduced growth, a strong decline in the PSI subunit PsaC and upregulation of proteins that might compensate for a non-functional co-translational CpSRP pathway during light stress conditions. The phenotype was highly similar to the one described for diatoms lacking another component of the co-translational CpSRP pathway, the CpSRP54 protein. However, in contrast to cpsrp54 mutants, only one thylakoid membrane protein, PetD of the Cytb6f complex, was downregulated in cpftsy. Our results point to a minor role for CpFTSY in the co-translational CpSRP pathway, suggesting that other mechanisms may partially compensate for the effect of a disrupted CpSRP pathway.
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Affiliation(s)
- Marianne Nymark
- Department of Biology, Norwegian University of Science and Technology, Trondheim N-7491, Norway
- Department of Fisheries and New Biomarine Industry, SINTEF Ocean, Trondheim 7010, Norway
| | - Giovanni Finazzi
- Cell & Plant Physiology Laboratory, Université Grenoble Alpes, CNRS, CEA, INRAE, IRIG, LPCV, Grenoble 38000, France
| | - Charlotte Volpe
- Department of Biology, Norwegian University of Science and Technology, Trondheim N-7491, Norway
- Department of Fisheries and New Biomarine Industry, SINTEF Ocean, Trondheim 7010, Norway
| | - Manuel Serif
- Department of Biology, Norwegian University of Science and Technology, Trondheim N-7491, Norway
| | - Davi de Miranda Fonseca
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NTNU, Trondheim N-7491, Norway
- Proteomics and Modomics Experimental Core Facility (PROMEC), NTNU and Central Administration, St. Olavs Hospital, The University Hospital in Trondheim, Trondheim N-7491, Norway
| | - Animesh Sharma
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NTNU, Trondheim N-7491, Norway
- Proteomics and Modomics Experimental Core Facility (PROMEC), NTNU and Central Administration, St. Olavs Hospital, The University Hospital in Trondheim, Trondheim N-7491, Norway
| | - Nicolas Sanchez
- Department of Chemistry, Norwegian University of Science and Technology, Trondheim N-7491, Norway
| | - Amit Kumar Sharma
- Department of Biology, Norwegian University of Science and Technology, Trondheim N-7491, Norway
| | - Felicity Ashcroft
- Department of Biology, Norwegian University of Science and Technology, Trondheim N-7491, Norway
| | - Ralph Kissen
- Department of Biology, Norwegian University of Science and Technology, Trondheim N-7491, Norway
| | - Per Winge
- Department of Biology, Norwegian University of Science and Technology, Trondheim N-7491, Norway
| | - Atle Magnar Bones
- Department of Biology, Norwegian University of Science and Technology, Trondheim N-7491, Norway
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18
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Huapaya K, Echeveste P. Physiological responses of Humboldt current system diatoms to Fe and Cu co-limitation. MARINE ENVIRONMENTAL RESEARCH 2023; 187:105937. [PMID: 36958199 DOI: 10.1016/j.marenvres.2023.105937] [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: 08/18/2022] [Revised: 02/26/2023] [Accepted: 02/28/2023] [Indexed: 06/18/2023]
Abstract
Diatoms account for ∼20% of global primary production, often limited by the availability of Fe and other trace nutrients such as Cu. The present study examined the role of both metals in the physiology of two diatoms isolated from the Humboldt Currents System, the centric Chaetoceros c.f. dicipiens and the pennate Nitzschia c.f. draveillensis. Under Fe limitation, a decrease in specific growth rates and sizes of both species was observed, especially in Chaetoceros. However, regarding different photosynthetic parameters, Nitzschia was more impacted. The increase in Cu concentrations improved the physiology of both diatoms, mostly of Chaetoceros. When grown in mixed cultures and under co-limiting conditions, both species remained competive due to morphological advantages (i.e., lower cell size). These results may suggest that the increase of Cu under Fe limitation benefited C. c.f. dicipiens over N. c.f. draveillensis.
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Affiliation(s)
- Katiuska Huapaya
- Instituto de Ciencias Naturales Alexander von Humboldt, Facultad de Ciencias Del Mar y Recursos Biológicos, Universidad de Antofagasta, Antofagasta, Chile.
| | - Pedro Echeveste
- Instituto de Ciencias Naturales Alexander von Humboldt, Facultad de Ciencias Del Mar y Recursos Biológicos, Universidad de Antofagasta, Antofagasta, Chile; Instituto Milenio de Oceanografía, Chile
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19
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Kang W, Sun S, Hu X. Microplastics trigger the Matthew effect on nitrogen assimilation in marine diatoms at an environmentally relevant concentration. WATER RESEARCH 2023; 233:119762. [PMID: 36841163 DOI: 10.1016/j.watres.2023.119762] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 02/15/2023] [Accepted: 02/17/2023] [Indexed: 06/18/2023]
Abstract
Microplastics (MPs, diameter <5 mm) are widely distributed on Earth, especially in the oceans. Diatoms account for ∼40% of marine primary productivity and affect the global biogeochemical cycles of macroelements. However, the effects of MPs on marine nitrogen cycling remain poorly understood, particularly comparisons between nitrogen-replete and nitrogen-limited conditions. We found that MPs trigger the Matthew effect on nitrogen assimilation in diatoms, where MPs inhibited nitrogen assimilation under nitrogen-limited conditions while enhancing nitrogen metabolism under nitrogen-replete conditions in Phaeodactylum tricornutum. Nitrate reductase (NR) and nitrite reductase (NIR) are upregulated, but nitrate transporter (NRT) and glutamine synthetase (GS) are downregulated by MPs under nitrogen-limited conditions. In contrast, NR, NIR, and GS are all upregulated by MPs under nitrogen-replete conditions. MPs accelerate nitrogen anabolic processes with an increase in the accumulation of carbohydrates by 80.7 ± 7.9% and enhance the activities of key nitrogen-metabolizing enzymes (8.20-44.90%) under nitrogen-replete conditions. In contrast, the abundance of carbohydrates decreases by 22.0-34.4%, and NRT activity is inhibited by 79.0-86.5% in nitrogen-limited algae exposed to MPs. Metabolomic and transcriptomic analyses were performed to further explore the molecular mechanisms of reprogrammed nitrogen assimilation, including carbon metabolism, nitrogen transport and ammonia assimilation. The aforementioned spatial redistribution (e.g., the Matthew effect between nitrogen-replete and -limited conditions) of nitrogen assimilation highlights the potential risks of MP contamination in the ocean.
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Affiliation(s)
- Weilu Kang
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Shan Sun
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Xiangang Hu
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
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20
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Rosa RM, Machado M, Vaz MGMV, Lopes-Santos R, Nascimento AGD, Araújo WL, Nunes-Nesi A. Urea as a source of nitrogen and carbon leads to increased photosynthesis rates in Chlamydomonas reinhardtii under mixotrophy. J Biotechnol 2023; 367:20-30. [PMID: 36966923 DOI: 10.1016/j.jbiotec.2023.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 03/23/2023] [Indexed: 03/31/2023]
Abstract
Microalgae is a potential source of bioproducts, including feedstock to biofuels. Urea has been pointed as potential N source for microalgae growth. Considering that urea metabolism releases HCO3- to the medium, we tested the hypothesis that this carbon source could improve photosynthesis and consequently growth rates of Chlamydomonas reinhardtii. In this sense, the metabolic responses of C. reinhardtii grown with ammonium and urea as nitrogen sources under mixotrophic and autotrophic conditions were investigated. Overall, the mixotrophy led to increased cell growth as well as to a higher accumulation of lipids independent of N source, followed by a decrease in photosynthesis over the growth phases. In mixotrophy, urea stimulates growth in terms of cell number and dry weight. Furthermore, higher photosynthesis was verified in late logarithmic phase compared to ammonium. Under autotrophy conditions, although cell number and biomass were reduced, there was higher production of starch independent of N source. Nonetheless, urea-based autotrophic treatments stimulated biomass production compared to ammonium-based treatment. Under mixotrophy higher input of carbon into the cell from acetate and urea optimized photosynthesis and consequently promoted cell growth. Together, these results suggest urea as alternative source of carbon, improving photosynthesis and cell growth in C. reinhardtii.
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21
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Ryan-Keogh TJ, Thomalla SJ, Monteiro PMS, Tagliabue A. Multidecadal trend of increasing iron stress in Southern Ocean phytoplankton. Science 2023; 379:834-840. [PMID: 36821685 DOI: 10.1126/science.abl5237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Southern Ocean primary productivity is principally controlled by adjustments in light and iron limitation, but the spatial and temporal determinants of iron availability, accessibility, and demand are poorly constrained, which hinders accurate long-term projections. We present a multidecadal record of phytoplankton photophysiology between 1996 and 2022 from historical in situ datasets collected by Biogeochemical Argo (BGC-Argo) floats and ship-based platforms. We find a significant multidecadal trend in irradiance-normalized nonphotochemical quenching due to increasing iron stress, with concomitant declines in regional net primary production. The observed trend of increasing iron stress results from changing Southern Ocean mixed-layer physics as well as complex biological and chemical feedback that is indicative of important ongoing changes to the Southern Ocean carbon cycle.
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Affiliation(s)
- Thomas J Ryan-Keogh
- Southern Ocean Carbon-Climate Observatory, CSIR, Cape Town 7700, South Africa
| | - Sandy J Thomalla
- Southern Ocean Carbon-Climate Observatory, CSIR, Cape Town 7700, South Africa
- Marine and Antarctic Research for Innovation and Sustainability, University of Cape Town, Cape Town 7700, South Africa
| | - Pedro M S Monteiro
- Southern Ocean Carbon-Climate Observatory, CSIR, Cape Town 7700, South Africa
- School for Climate Studies, Stellenbosch University, Stellenbosch 7602, South Africa
| | - Alessandro Tagliabue
- Department of Earth, Ocean and Ecological Sciences, School of Environmental Sciences, University of Liverpool, Liverpool L69 3GP, UK
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22
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Behnke J, Cai Y, Gu H, LaRoche J. Short-term response to iron resupply in an iron-limited open ocean diatom reveals rapid decay of iron-responsive transcripts. PLoS One 2023; 18:e0280827. [PMID: 36693065 PMCID: PMC9873189 DOI: 10.1371/journal.pone.0280827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 01/09/2023] [Indexed: 01/25/2023] Open
Abstract
In large areas of the ocean, iron concentrations are insufficient to promote phytoplankton growth. Numerous studies have been conducted to characterize the effect of iron on algae and how algae cope with fluctuating iron concentrations. Fertilization experiments in low-iron areas resulted primarily in diatom-dominated algal blooms, leading to laboratory studies on diatoms comparing low- and high-iron conditions. Here, we focus on the short-term temporal response following iron addition to an iron-starved open ocean diatom, Thalassiosira oceanica. We employed the NanoString platform and analyzed a high-resolution time series on 54 transcripts encoding proteins involved in photosynthesis, N-linked glycosylation, iron transport, as well as transcription factors. Nine transcripts were iron-responsive, with an immediate response to the addition of iron. The fastest response observed was the decrease in transcript levels of proteins involved in iron uptake, followed by an increase in transcript levels of iron-containing enzymes and a simultaneous decrease in the transcript levels of their iron-free replacement enzymes. The transcription inhibitor actinomycin D was used to understand the underlying mechanisms of the decrease of the iron-responsive transcripts and to determine their half-lives. Here, Mn-superoxide dismutase (Mn-SOD), plastocyanin (PETE), ferredoxin (PETF) and cellular repressor of EA1-stimulated genes (CREGx2) revealed longer than average half-lives. Four iron-responsive transcripts showed statistically significant differences in their decay rates between the iron-recovery samples and the actD treatment. These differences suggest regulatory mechanisms influencing gene transcription and mRNA stability. Overall, our study contributes towards a detailed understanding of diatom cell biology in the context of iron fertilization response and provides important observations to assess oceanic diatom responses following sudden changes in iron concentrations.
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Affiliation(s)
- Joerg Behnke
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
- * E-mail: (JB); (JL)
| | - Yun Cai
- Department of Mathematics & Statistics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Hong Gu
- Department of Mathematics & Statistics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Julie LaRoche
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
- * E-mail: (JB); (JL)
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23
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Kabir AH, Ela EJ, Bagchi R, Rahman MA, Peiter E, Lee KW. Nitric oxide acts as an inducer of Strategy-I responses to increase Fe availability and mobilization in Fe-starved broccoli (Brassica oleracea var. oleracea). PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 194:182-192. [PMID: 36423388 DOI: 10.1016/j.plaphy.2022.11.018] [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: 08/20/2022] [Revised: 11/10/2022] [Accepted: 11/14/2022] [Indexed: 06/16/2023]
Abstract
Iron (Fe) deficiency causes reduced growth and yield in broccoli. This study elucidates how sodium nitroprusside (SNP), known as nitric oxide (NO) donor, mitigates the retardation caused by Fe deficiency in broccoli. The SNP caused substantial nitric oxide accumulation in the roots of Fe-deficient plants, which resulted in a significant improvement in chlorophyll levels, photosynthetic efficiency, and morphological growth parameters, showing that it has a favorable influence on recovering broccoli health. Ferric reductase activity and the expression of BoFRO1 (ferric chelate reductase) gene in roots were consistently increased by SNP under Fe deficiency, which likely resulted in increased Fe mobilization. Furthermore, proton (H+) extrusion and BoHA2 (H+-ATPase 2) expression were significantly increased, suggesting that they may be involved in lowering rhizospheric pH to restore Fe mobilization in roots of bicarbonate-treated broccoli plants. The levels of Fe in root and shoot tissues and the expression of BoIRT1 (Fe-regulated transporter) both increased dramatically after SNP supplementation under Fe deprivation. Furthermore, SNP-induced increase in citrate and malate concentrations suggested a role of NO in improved Fe chelation in Fe-deficient broccoli. A NO scavenger (cPTIO) ceased the elevated FCR activity and IAA (indole-3-acetic acid) concentration in Fe-starved plants treated with SNP. These findings suggest that SNP may play a role in initiating Fe availability by elevated IAA concentration and BoEIR1 (auxin efflux carrier) expression in the roots of broccoli during Fe shortage. Therefore, SNP may improve Fe availability and mobilization by increasing Strategy-I Fe uptake pathways, which may help broccoli tolerate Fe deficiency.
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Affiliation(s)
- Ahmad Humayan Kabir
- Department of Genetics, University of Georgia, GA 30602, USA; Molecular Plant Physiology Laboratory, University of Rajshahi, Rajshahi, 6205, Bangladesh.
| | - Esrat Jahan Ela
- Molecular Plant Physiology Laboratory, University of Rajshahi, Rajshahi, 6205, Bangladesh
| | - Ruby Bagchi
- Molecular Plant Physiology Laboratory, University of Rajshahi, Rajshahi, 6205, Bangladesh
| | - Md Atikur Rahman
- Grassland and Forage Division, National Institute of Animal Science, Rural Development Administration, Cheonan, 31000, Republic of Korea
| | - Edgar Peiter
- Plant Nutrition Laboratory, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Ki-Won Lee
- Grassland and Forage Division, National Institute of Animal Science, Rural Development Administration, Cheonan, 31000, Republic of Korea
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24
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Kazamia E, Mach J, McQuaid JB, Gao X, Coale TH, Malych R, Camadro J, Lesuisse E, Allen AE, Bowler C, Sutak R. In vivo localization of iron starvation induced proteins under variable iron supplementation regimes in Phaeodactylum tricornutum. PLANT DIRECT 2022; 6:e472. [PMID: 36582220 PMCID: PMC9792268 DOI: 10.1002/pld3.472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 11/03/2022] [Accepted: 11/30/2022] [Indexed: 06/17/2023]
Abstract
UNLABELLED The model pennate diatom Phaeodactylum tricornutum is able to assimilate a range of iron sources. It therefore provides a platform to study different mechanisms of iron processing concomitantly in the same cell. In this study, we follow the localization of three iron starvation induced proteins (ISIPs) in vivo, driven by their native promoters and tagged by fluorophores in an engineered line of P. tricornutum. We find that the localization patterns of ISIPs are dynamic and variable depending on the overall iron status of the cell and the source of iron it is exposed to. Notwithstanding, a shared destination of the three ISIPs both under ferric iron and siderophore-bound iron supplementation is a globular compartment in the vicinity of the chloroplast. In a proteomic analysis, we identify that the cell engages endocytosis machinery involved in the vesicular trafficking as a response to siderophore molecules, even when these are not bound to iron. Our results suggest that there may be a direct vesicle traffic connection between the diatom cell membrane and the periplastidial compartment (PPC) that co-opts clathrin-mediated endocytosis and the "cytoplasm to vacuole" (Cvt) pathway, for proteins involved in iron assimilation. Proteomics data are available via ProteomeXchange with identifier PXD021172. HIGHLIGHT The marine diatom P. tricornutum engages a vesicular network to traffic siderophores and phytotransferrin from the cell membrane directly to a putative iron processing site in the vicinity of the chloroplast.
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Affiliation(s)
- Elena Kazamia
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERMUniversité PSLParisFrance
| | - Jan Mach
- Department of Parasitology, Faculty of ScienceCharles UniversityVestecCzech Republic
| | - Jeffrey B. McQuaid
- Microbial and Environmental GenomicsJ. Craig Venter InstituteLa JollaCaliforniaUSA
- The Alfred Wegener InstituteHelmholtz Centre for Polar and Marine ResearchBremerhavenGermany
| | - Xia Gao
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERMUniversité PSLParisFrance
| | - Tyler H. Coale
- Scripps Institution of Oceanography, Integrative Oceanography DivisionUniversity of California, San DiegoLa JollaCaliforniaUSA
| | - Ronald Malych
- Department of Parasitology, Faculty of ScienceCharles UniversityVestecCzech Republic
| | | | | | - Andrew E. Allen
- Microbial and Environmental GenomicsJ. Craig Venter InstituteLa JollaCaliforniaUSA
- Scripps Institution of Oceanography, Integrative Oceanography DivisionUniversity of California, San DiegoLa JollaCaliforniaUSA
| | - Chris Bowler
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERMUniversité PSLParisFrance
| | - Robert Sutak
- Department of Parasitology, Faculty of ScienceCharles UniversityVestecCzech Republic
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25
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Nef C, Madoui MA, Pelletier É, Bowler C. Whole-genome scanning reveals environmental selection mechanisms that shape diversity in populations of the epipelagic diatom Chaetoceros. PLoS Biol 2022; 20:e3001893. [PMID: 36441816 PMCID: PMC9731442 DOI: 10.1371/journal.pbio.3001893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 12/08/2022] [Accepted: 10/27/2022] [Indexed: 11/30/2022] Open
Abstract
Diatoms form a diverse and abundant group of photosynthetic protists that are essential players in marine ecosystems. However, the microevolutionary structure of their populations remains poorly understood, particularly in polar regions. Exploring how closely related diatoms adapt to different environments is essential given their short generation times, which may allow rapid adaptations, and their prevalence in marine regions dramatically impacted by climate change, such as the Arctic and Southern Oceans. Here, we address genetic diversity patterns in Chaetoceros, the most abundant diatom genus and one of the most diverse, using 11 metagenome-assembled genomes (MAGs) reconstructed from Tara Oceans metagenomes. Genome-resolved metagenomics on these MAGs confirmed a prevalent distribution of Chaetoceros in the Arctic Ocean with lower dispersal in the Pacific and Southern Oceans as well as in the Mediterranean Sea. Single-nucleotide variants identified within the different MAG populations allowed us to draw a landscape of Chaetoceros genetic diversity and revealed an elevated genetic structure in some Arctic Ocean populations. Gene flow patterns of closely related Chaetoceros populations seemed to correlate with distinct abiotic factors rather than with geographic distance. We found clear positive selection of genes involved in nutrient availability responses, in particular for iron (e.g., ISIP2a, flavodoxin), silicate, and phosphate (e.g., polyamine synthase), that were further supported by analysis of Chaetoceros transcriptomes. Altogether, these results highlight the importance of environmental selection in shaping diatom diversity patterns and provide new insights into their metapopulation genomics through the integration of metagenomic and environmental data.
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Affiliation(s)
- Charlotte Nef
- Institut de Biologie de l’École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, PSL Université Paris, Paris, France
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans, Paris, France
| | - Mohammed-Amin Madoui
- Service d’Etude des Prions et des Infections Atypiques (SEPIA), Institut François Jacob, Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Université Paris Saclay, Fontenay-aux-Roses, France
- Équipe Écologie Évolutive, UMR CNRS 6282 BioGéoSciences, Université de Bourgogne Franche-Comté, Dijon, 21000, France
| | - Éric Pelletier
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans, Paris, France
- Metabolic Genomics, Genoscope, Institut de Biologie François-Jacob, CEA, CNRS, Université Evry, Université Paris Saclay, Evry, France
| | - Chris Bowler
- Institut de Biologie de l’École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, PSL Université Paris, Paris, France
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans, Paris, France
- * E-mail:
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26
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Li L, Delgado‐Viscogliosi P, Gerphagnon M, Viscogliosi E, Christaki U, Sime‐Ngando T, Monchy S. Taxonomic and functional dynamics during chytrid epidemics in an aquatic ecosystem. Mol Ecol 2022; 31:5618-5634. [PMID: 36028992 PMCID: PMC9826485 DOI: 10.1111/mec.16675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 08/16/2022] [Accepted: 08/18/2022] [Indexed: 01/11/2023]
Abstract
Fungal parasitism is common in plankton communities and plays a crucial role in the ecosystem by balancing nutrient cycling in the food web. Previous studies of aquatic ecosystems revealed that zoosporic chytrid epidemics represent an important driving factor in phytoplankton seasonal successions. In this study, host-parasite dynamics in Lake Pavin (France) were investigated during the spring diatom bloom while following chytrid epidemics using next generation sequencing (NGS). Metabarcoding analyses were applied to study changes in the eukaryotic microbial community throughout diatom bloom-chytrid epidemics. Relative read abundances of metabarcoding data revealed potential "beneficiaries" and "victims" during the studied period. Subsequently, metatranscriptomic analyses on samples before and during the chytrid epidemic unveiled the active part of the community and functional/metabolic dynamics in association with the progress of chytrid infection. Diatom functions involving lipases, transporters, histones, vacuolar systems, the proteasome, proteases and DNA/RNA polymerases were more abundant during the diatom bloom. Chytrid functions related to a parasitic lifestyle including invasion, colonization and stress tolerance were up-regulated during the chytrid epidemic. In addition, functions related to the degradation/metabolism of proteins, lipids and chitin were in higher proportion in the community during the epidemic event. Results of NGS and bioinformatics analyses offered a panorama of dynamic biodiversity and biological functioning of the community.
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Affiliation(s)
- Luen‐Luen Li
- Université du Littoral Côte d'Opale, CNRS, Univ. Lille, UMR 8187, LOGLaboratoire d'Océanologie et de GéosciencesWimereuxFrance
| | - Pilar Delgado‐Viscogliosi
- University of Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de LilleU1019 – UMR 9017 – CIIL – Centre d'’Infection et d'’Immunité de LilleLilleFrance
| | - Mélanie Gerphagnon
- Laboratoire Microorganismes: Génome et Environnement, UMR CNRS 6023Clermont Université, Blaise PascalAubièreFrance
| | - Eric Viscogliosi
- University of Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de LilleU1019 – UMR 9017 – CIIL – Centre d'’Infection et d'’Immunité de LilleLilleFrance
| | - Urania Christaki
- Université du Littoral Côte d'Opale, CNRS, Univ. Lille, UMR 8187, LOGLaboratoire d'Océanologie et de GéosciencesWimereuxFrance
| | - Télesphore Sime‐Ngando
- Laboratoire Microorganismes: Génome et Environnement, UMR CNRS 6023Clermont Université, Blaise PascalAubièreFrance
| | - Sébastien Monchy
- Université du Littoral Côte d'Opale, CNRS, Univ. Lille, UMR 8187, LOGLaboratoire d'Océanologie et de GéosciencesWimereuxFrance
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27
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Kabir AH, Rahman MA, Rahman MM, Brailey‐Jones P, Lee K, Bennetzen JL. Mechanistic assessment of tolerance to iron deficiency mediated by Trichoderma harzianum in soybean roots. J Appl Microbiol 2022; 133:2760-2778. [PMID: 35665578 PMCID: PMC9796762 DOI: 10.1111/jam.15651] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/24/2022] [Accepted: 05/31/2022] [Indexed: 01/07/2023]
Abstract
AIMS Iron (Fe) deficiency in soil is a continuing problem for soybean (Glycine max L.) production, partly as a result of continuing climate change. This study elucidates how Trichoderma harzianum strain T22 (TH) mitigates growth retardation associated with Fe-deficiency in a highly sensitive soybean cultivar. METHODS AND RESULTS Soil TH supplementation led to mycelial colonization and the presence of UAOX1 gene in roots that caused substantial improvement in chlorophyll score, photosynthetic efficiency and morphological parameters, indicating a positive influence on soybean health. Although rhizosphere acidification was found to be a common feature of Fe-deficient soybean, the upregulation of Fe-reductase activity (GmFRO2) and total phenol secretion were two of the mechanisms that substantially increased the Fe availability by TH. Heat-killed TH applied to soil caused no improvement in photosynthetic attributes and Fe-reductase activity, confirming the active role of TH in mitigating Fe-deficiency. Consistent increases in tissue Fe content and increased Fe-transporter (GmIRT1, GmNRAMP2a, GmNRAMP2b and GmNRAMP7) mRNA levels in roots following TH supplementation were observed only under Fe-deprivation. Root cell death, electrolyte leakage, superoxide (O2 •- ) and hydrogen peroxide (H2 O2 ) substantially declined due to TH in Fe-deprived plants. Further, the elevation of citrate and malate concentration along with the expression of citrate synthase (GmCs) and malate synthase (GmMs) caused by TH suggest improved chelation of Fe in Fe-deficient plants. Results also suggest that TH has a role in triggering antioxidant defence by increasing the activity of glutathione reductase (GR) along with elevated S-metabolites (glutathione and methionine) to stabilize redox status under Fe-deficiency. CONCLUSIONS TH increases the availability and mobilization of Fe by inducing Fe-uptake pathways, which appears to help provide resistance to oxidative stress associated with Fe-shortage in soybean. SIGNIFICANCE AND IMPACT OF THE STUDY These findings indicate that while Fe deficiency does not affect the rate or degree of TH hyphal association in soybean roots, the beneficial effects of TH alone may be Fe deficiency-dependent.
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Affiliation(s)
- Ahmad Humayan Kabir
- Molecular Plant Physiology Laboratory, Department of BotanyUniversity of RajshahiRajshahiBangladesh
- Department of GeneticsUniversity of GeorgiaAthensGAUSA
| | - Md Atikur Rahman
- Grassland and Forage Division, National Institute of Animal ScienceRural Development AdministrationCheonanRepublic of Korea
| | - Md Mostafizur Rahman
- Molecular Plant Physiology Laboratory, Department of BotanyUniversity of RajshahiRajshahiBangladesh
| | - Philip Brailey‐Jones
- Grassland and Forage Division, National Institute of Animal ScienceRural Development AdministrationCheonanRepublic of Korea
| | - Ki‐Won Lee
- Department of GeneticsUniversity of GeorgiaAthensGAUSA
| | - Jeffrey L. Bennetzen
- Grassland and Forage Division, National Institute of Animal ScienceRural Development AdministrationCheonanRepublic of Korea
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28
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Lupette J, Tardif M, Brugière S, Couté Y, Salvaing J, Maréchal E. Quantitative proteomic analyses reveal the impact of nitrogen starvation on the proteome of the model diatom Phaeodactylum tricornutum. Proteomics 2022; 22:e2200155. [PMID: 36168874 DOI: 10.1002/pmic.202200155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 09/13/2022] [Accepted: 09/14/2022] [Indexed: 12/29/2022]
Abstract
Diatoms are one of the largest groups in phytoplankton biodiversity. Understanding their response to nitrogen variations, present from micromolar to near-zero levels in oceans and fresh waters, is essential to comprehend their ecological success. Nitrogen starvation is used in biotechnological processes, to trigger the remodeling of carbon metabolism in the direction of fatty acids and triacylglycerol synthesis. We evaluated whole proteome changes in Phaeodactylum tricornutum after 7 days of cultivation with 5.5-mM nitrate (+N) or without any nitrogen source (-N). On a total of 3768 proteins detected in biological replicates, our analysis pointed to 384 differentially abundant proteins (DAP). Analysis of proteins of lower abundance in -N revealed an arrest of amino acid and protein syntheses, a remodeling of nitrogen metabolism, and a decrease of the proteasome abundance suggesting a decline in unselective whole-proteome decay. Analysis of proteins of higher abundance revealed the setting up of a general nitrogen scavenging system dependent on deaminases. The increase of a plastid palmitoyl-ACP desaturase appeared as a hallmark of carbon metabolism rewiring in the direction of fatty acid and triacylglycerol synthesis. This dataset is also valuable to select gene candidates for improved biotechnological properties.
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Affiliation(s)
- Josselin Lupette
- Laboratoire de Physiologie Cellulaire et Végétale, CEA, CNRS, INRAE, Université Grenoble Alpes, IRIG, CEA Grenoble, Grenoble, France.,Laboratoire de Biogenèse Membranaire, CNRS, Université de Bordeaux, Villenave d'Ornon, France
| | - Marianne Tardif
- Université Grenoble Alpes, INSERM, CEA, UMR BioSanté U1292, CNRS, CEA, FR2048, Grenoble, France
| | - Sabine Brugière
- Université Grenoble Alpes, INSERM, CEA, UMR BioSanté U1292, CNRS, CEA, FR2048, Grenoble, France
| | - Yohann Couté
- Université Grenoble Alpes, INSERM, CEA, UMR BioSanté U1292, CNRS, CEA, FR2048, Grenoble, France
| | - Juliette Salvaing
- Laboratoire de Physiologie Cellulaire et Végétale, CEA, CNRS, INRAE, Université Grenoble Alpes, IRIG, CEA Grenoble, Grenoble, France
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire et Végétale, CEA, CNRS, INRAE, Université Grenoble Alpes, IRIG, CEA Grenoble, Grenoble, France
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Nitrogen and Iron Availability Drive Metabolic Remodeling and Natural Selection of Diverse Phytoplankton during Experimental Upwelling. mSystems 2022; 7:e0072922. [PMID: 36036504 PMCID: PMC9599627 DOI: 10.1128/msystems.00729-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Nearly half of carbon fixation and primary production originates from marine phytoplankton, and much of it occurs in episodic blooms in upwelling regimes. Here, we simulated blooms limited by nitrogen and iron by incubating Monterey Bay surface waters with subnutricline waters and inorganic nutrients and measured the whole-community transcriptomic response during mid- and late-bloom conditions. Cell counts revealed that centric and pennate diatoms (largely Pseudo-nitzschia and Chaetoceros spp.) were the major blooming taxa, but dinoflagellates, prasinophytes, and prymnesiophytes also increased. Viral mRNA significantly increased in late bloom and likely played a role in the bloom's demise. We observed conserved shifts in the genetic similarity of phytoplankton populations to cultivated strains, indicating adaptive population-level changes in community composition. Additionally, the density of single nucleotide variants (SNVs) declined in late-bloom samples for most taxa, indicating a loss of intraspecific diversity as a result of competition and a selective sweep of adaptive alleles. We noted differences between mid- and late-bloom metabolism and differential regulation of light-harvesting complexes (LHCs) under nutrient stress. While most LHCs are diminished under nutrient stress, we showed that diverse taxa upregulated specialized, energy-dissipating LHCs in low iron. We also suggest the relative expression of NRT2 compared to the expression of GSII as a marker of cellular nitrogen status and the relative expression of iron starvation-induced protein genes (ISIP1, ISIP2, and ISIP3) compared to the expression of the thiamine biosynthesis gene (thiC) as a marker of iron status in natural diatom communities. IMPORTANCE Iron and nitrogen are the nutrients that most commonly limit phytoplankton growth in the world's oceans. The utilization of these resources by phytoplankton sets the biomass available to marine systems and is of particular interest in high-nutrient, low-chlorophyll (HNLC) coastal fisheries. Previous research has described the biogeography of phytoplankton in HNLC regions and the transcriptional responses of representative taxa to nutrient limitation. However, the differential transcriptional responses of whole phytoplankton communities to iron and nitrogen limitation has not been previously described, nor has the selective pressure that these competitive bloom environments exert on major players. In addition to describing changes in the physiology of diverse phytoplankton, we suggest practical indicators of cellular nitrogen and iron status for future monitoring.
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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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31
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Lacour T, Larivière J, Ferland J, Morin PI, Grondin PL, Donaher N, Cockshutt A, Campbell DA, Babin M. Photoacclimation of the polar diatom Chaetoceros neogracilis at low temperature. PLoS One 2022; 17:e0272822. [PMID: 36125987 PMCID: PMC9488821 DOI: 10.1371/journal.pone.0272822] [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: 03/31/2022] [Accepted: 07/26/2022] [Indexed: 11/18/2022] Open
Abstract
Polar microalgae face two major challenges: 1- growing at temperatures (-1.7 to 5°C) that limit enzyme kinetics; and 2- surviving and exploiting a wide range of irradiance. The objective of this study is to understand the adaptation of an Arctic diatom to its environment by studying its ability to acclimate to changes in light and temperature. We acclimated the polar diatom Chaetoceros neogracilis to various light levels at two different temperatures and studied its growth and photosynthetic properties using semi-continuous cultures. Rubisco content was high, to compensate for low catalytic rates, but did not change detectably with growth temperature. Contrary to what is observed in temperate species, in C. neogracilis, carbon fixation rate (20 min 14C incorporation) equaled net growth rate (μ) suggesting very low or very rapid (<20 min) re-oxidation of the newly fixed carbon. The comparison of saturation irradiances for electron transport, oxygen net production and carbon fixation revealed alternative electron pathways that could provide energy and reducing power to the cell without consuming organic carbon which is a very limiting product at low temperatures. High protein contents, low re-oxidation of newly fixed carbon and the use of electron pathways alternative to carbon fixation may be important characteristics allowing efficient growth under those extreme environmental conditions.
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Affiliation(s)
- Thomas Lacour
- Ifremer, PHYTOX, PHYSALG, Brest, France
- Département de Biologie, Takuvik International Research Laboratory (IRL-3376, CNRS (France) & ULaval (Canada), Université Laval, Québec, Canada
- * E-mail:
| | - Jade Larivière
- Département de Biologie, Takuvik International Research Laboratory (IRL-3376, CNRS (France) & ULaval (Canada), Université Laval, Québec, Canada
| | - Joannie Ferland
- Département de Biologie, Takuvik International Research Laboratory (IRL-3376, CNRS (France) & ULaval (Canada), Université Laval, Québec, Canada
| | - Philippe-Israël Morin
- Département de Biologie, Takuvik International Research Laboratory (IRL-3376, CNRS (France) & ULaval (Canada), Université Laval, Québec, Canada
| | - Pierre-Luc Grondin
- Département de Biologie, Takuvik International Research Laboratory (IRL-3376, CNRS (France) & ULaval (Canada), Université Laval, Québec, Canada
| | - Natalie Donaher
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, Canada
| | - Amanda Cockshutt
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, Canada
| | - Douglas A. Campbell
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, Canada
| | - Marcel Babin
- Département de Biologie, Takuvik International Research Laboratory (IRL-3376, CNRS (France) & ULaval (Canada), Université Laval, Québec, Canada
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Maniscalco MA, Brzezinski MA, Lampe RH, Cohen NR, McNair HM, Ellis KA, Brown M, Till CP, Twining BS, Bruland KW, Marchetti A, Thamatrakoln K. Diminished carbon and nitrate assimilation drive changes in diatom elemental stoichiometry independent of silicification in an iron-limited assemblage. ISME COMMUNICATIONS 2022; 2:57. [PMID: 37938259 PMCID: PMC9723790 DOI: 10.1038/s43705-022-00136-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 05/12/2022] [Accepted: 06/09/2022] [Indexed: 06/17/2023]
Abstract
In the California Current Ecosystem, upwelled water low in dissolved iron (Fe) can limit phytoplankton growth, altering the elemental stoichiometry of the particulate matter and dissolved macronutrients. Iron-limited diatoms can increase biogenic silica (bSi) content >2-fold relative to that of particulate organic carbon (C) and nitrogen (N), which has implications for carbon export efficiency given the ballasted nature of the silica-based diatom cell wall. Understanding the molecular and physiological drivers of this altered cellular stoichiometry would foster a predictive understanding of how low Fe affects diatom carbon export. In an artificial upwelling experiment, water from 96 m depth was incubated shipboard and left untreated or amended with dissolved Fe or the Fe-binding siderophore desferrioxamine-B (+DFB) to induce Fe-limitation. After 120 h, diatoms dominated the communities in all treatments and displayed hallmark signatures of Fe-limitation in the +DFB treatment, including elevated particulate Si:C and Si:N ratios. Single-cell, taxon-resolved measurements revealed no increase in bSi content during Fe-limitation despite higher transcript abundance of silicon transporters and silicanin-1. Based on these findings we posit that the observed increase in bSi relative to C and N was primarily due to reductions in C fixation and N assimilation, driven by lower transcript expression of key Fe-dependent genes.
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Affiliation(s)
- Michael A Maniscalco
- Marine Science Institute and The Department of Ecology Evolution and Marine Biology, University of California, Santa Barbara, CA, USA.
| | - Mark A Brzezinski
- Marine Science Institute and The Department of Ecology Evolution and Marine Biology, University of California, Santa Barbara, CA, USA
| | - Robert H Lampe
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA
| | - Natalie R Cohen
- Skidaway Institute of Oceanography, University of Georgia, Savannah, GA, USA
| | - Heather M McNair
- University of Rhode Island, Graduate School of Oceanography, Narragansett, RI, USA
| | - Kelsey A Ellis
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, USA
| | | | - Claire P Till
- Chemistry Department, California State Polytechnic University, Humboldt, Arcata, CA, USA
| | | | - Kenneth W Bruland
- Department of Ocean Sciences, University of California, Santa Cruz, CA, USA
| | - Adrian Marchetti
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, USA
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33
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Slattery SS, Giguere DJ, Stuckless EE, Shrestha A, Briere LAK, Galbraith A, Reaume S, Boyko X, Say HH, Browne TS, Frederick MI, Lant JT, Heinemann IU, O'Donoghue P, Dsouza L, Martin S, Howard P, Jedeszko C, Ali K, Styba G, Flatley M, Karas BJ, Gloor GB, Edgell DR. Phosphate-regulated expression of the SARS-CoV-2 receptor-binding domain in the diatom Phaeodactylum tricornutum for pandemic diagnostics. Sci Rep 2022; 12:7010. [PMID: 35487958 PMCID: PMC9051505 DOI: 10.1038/s41598-022-11053-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 04/18/2022] [Indexed: 12/22/2022] Open
Abstract
The worldwide COVID-19 pandemic caused by the SARS-CoV-2 betacoronavirus has highlighted the need for a synthetic biology approach to create reliable and scalable sources of viral antigen for uses in diagnostics, therapeutics and basic biomedical research. Here, we adapt plasmid-based systems in the eukaryotic microalgae Phaeodactylum tricornutum to develop an inducible overexpression system for SARS-CoV-2 proteins. Limiting phosphate and iron in growth media induced expression of the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein from the P. tricornutum HASP1 promoter in the wild-type strain and in a histidine auxotrophic strain that alleviates the requirement for antibiotic selection of expression plasmids. The RBD was purified from whole cell extracts (algae-RBD) with yield compromised by the finding that 90-95% of expressed RBD lacked the genetically encoded C-terminal 6X-histidine tag. Constructs that lacked the TEV protease site between the RBD and C-terminal 6X-histidine tag retained the tag, increasing yield. Purified algae-RBD was found to be N-linked glycosylated by treatment with endoglycosidases, was cross-reactive with anti-RBD polyclonal antibodies, and inhibited binding of recombinant RBD purified from mammalian cell lines to the human ACE2 receptor. We also show that the algae-RBD can be used in a lateral flow assay device to detect SARS-CoV-2 specific IgG antibodies from donor serum at sensitivity equivalent to assays performed with RBD made in mammalian cell lines. Our study shows that P. tricornutum is a scalable system with minimal biocontainment requirements for the inducible production of SARS-CoV-2 or other coronavirus antigens for pandemic diagnostics.
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Affiliation(s)
- Samuel S Slattery
- Department of Biochemistry, Schlich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada
| | - Daniel J Giguere
- Department of Biochemistry, Schlich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada
| | - Emily E Stuckless
- Department of Biochemistry, Schlich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada
| | - Arina Shrestha
- Department of Biochemistry, Schlich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada
| | - Lee-Ann K Briere
- Department of Biochemistry, Schlich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada
| | - Alexa Galbraith
- Lambton College, 1457 London Rd, Sarnia, ON, N7S 6K4, Canada
| | - Stephen Reaume
- Lambton College, 1457 London Rd, Sarnia, ON, N7S 6K4, Canada
| | - Xenia Boyko
- Department of Biochemistry, Schlich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada
| | - Henry H Say
- Department of Biochemistry, Schlich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada
| | - Tyler S Browne
- Department of Biochemistry, Schlich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada
| | - Mallory I Frederick
- Department of Biochemistry, Schlich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada
| | - Jeremy T Lant
- Department of Biochemistry, Schlich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada
| | - Ilka U Heinemann
- Department of Biochemistry, Schlich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada
| | - Patrick O'Donoghue
- Department of Biochemistry, Schlich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada
- Department of Chemistry, Western University, London, ON, N6A 3K7, Canada
| | - Liann Dsouza
- Pond Technologies Inc., Markham, ON, L3R 9W7, Canada
| | - Steven Martin
- Pond Technologies Inc., Markham, ON, L3R 9W7, Canada
| | - Peter Howard
- Pond Technologies Inc., Markham, ON, L3R 9W7, Canada
| | - Christopher Jedeszko
- International Point of Care Inc., 135 The West Mall Unit 9, Toronto, ON, M9C 1C2, Canada
| | - Kinza Ali
- International Point of Care Inc., 135 The West Mall Unit 9, Toronto, ON, M9C 1C2, Canada
| | - Garth Styba
- International Point of Care Inc., 135 The West Mall Unit 9, Toronto, ON, M9C 1C2, Canada
| | - Martin Flatley
- Suncor Energy Inc., Sarnia Refinery, 1900 River Road, Sarnia, ON, N7T 7J3, Canada
| | - Bogumil J Karas
- Department of Biochemistry, Schlich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada
| | - Gregory B Gloor
- Department of Biochemistry, Schlich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada.
| | - David R Edgell
- Department of Biochemistry, Schlich School of Medicine and Dentistry, Western University, London, ON, N6A 5C1, Canada.
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Gilbertson R, Langan E, Mock T. Diatoms and Their Microbiomes in Complex and Changing Polar Oceans. Front Microbiol 2022; 13:786764. [PMID: 35401494 PMCID: PMC8991070 DOI: 10.3389/fmicb.2022.786764] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 02/23/2022] [Indexed: 11/17/2022] Open
Abstract
Diatoms, a key group of polar marine microbes, support highly productive ocean ecosystems. Like all life on earth, diatoms do not live in isolation, and they are therefore under constant biotic and abiotic pressures which directly influence their evolution through natural selection. Despite their importance in polar ecosystems, polar diatoms are understudied compared to temperate species. The observed rapid change in the polar climate, especially warming, has created increased research interest to discover the underlying causes and potential consequences on single species to entire ecosystems. Next-Generation Sequencing (NGS) technologies have greatly expanded our knowledge by revealing the molecular underpinnings of physiological adaptations to polar environmental conditions. Their genomes, transcriptomes, and proteomes together with the first eukaryotic meta-omics data of surface ocean polar microbiomes reflect the environmental pressures through adaptive responses such as the expansion of protein families over time as a consequence of selection. Polar regions and their microbiomes are inherently connected to climate cycles and their feedback loops. An integrated understanding built on “omics” resources centered around diatoms as key primary producers will enable us to reveal unifying concepts of microbial co-evolution and adaptation in polar oceans. This knowledge, which aims to relate past environmental changes to specific adaptations, will be required to improve climate prediction models for polar ecosystems because it provides a unifying framework of how interacting and co-evolving biological communities might respond to future environmental change.
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Affiliation(s)
- Reuben Gilbertson
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Emma Langan
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom.,The Earlham Institute, Norwich Research Park, Norwich, United Kingdom
| | - Thomas Mock
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
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35
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Chuberre C, Chan P, Walet-Balieu ML, Thiébert F, Burel C, Hardouin J, Gügi B, Bardor M. Comparative Proteomic Analysis of the Diatom Phaeodactylum tricornutum Reveals New Insights Into Intra- and Extra-Cellular Protein Contents of Its Oval, Fusiform, and Triradiate Morphotypes. FRONTIERS IN PLANT SCIENCE 2022; 13:673113. [PMID: 35386671 PMCID: PMC8977783 DOI: 10.3389/fpls.2022.673113] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 02/01/2022] [Indexed: 06/14/2023]
Abstract
Phaeodactylum tricornutum is an atypical diatom since it can display three main morphotypes: fusiform, triradiate, and oval. Such pleomorphism is possible thanks to an original metabolism, which is tightly regulated in order to acclimate to environmental conditions. Currently, studies dedicated to the comparison of each morphotype issued from one specific strain are scarce and little information is available regarding the physiological significance of this morphogenesis. In this study, we performed a comparative proteomic analysis of the three morphotypes from P. tricornutum. Cultures highly enriched in one dominant morphotype (fusiform, triradiate, or oval) of P. tricornutum Pt3 strain were used. Pairwise comparisons highlighted biological processes, which are up- and down-regulated in the oval (e.g., purine and cellular amino acid metabolism) and triradiate morphotypes (e.g., oxido-reduction and glycolytic processes) compared to the fusiform one used as a reference. Intersection analysis allowed us to identify the specific features of the oval morphotype. Results from this study confirmed previous transcriptomic RNA sequencing observation showing that the oval cells present a distinct metabolism with specific protein enrichment compared to fusiform and triradiate cells. Finally, the analysis of the secretome of each morphotype was also performed.
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Affiliation(s)
- Coralie Chuberre
- UNIROUEN, Laboratoire Glyco-MEV EA4358, Normandie Université, Rouen, France
| | - Philippe Chan
- UNIROUEN, PISSARO Proteomic Facility, Institute for Research and Innovation in Biomedicine, Normandie Université, Mont-Saint-Aignan, France
- Normandie University, UNIROUEN, INSERM US 51, CNRS UAR 2026, HeRacLeS-PISSARO, Rouen, France
- UNIROUEN, Institute for Research and Innovation in Biomedicine, Normandie Université, Rouen, France
| | | | - François Thiébert
- UNIROUEN, Laboratoire Glyco-MEV EA4358, Normandie Université, Rouen, France
| | - Carole Burel
- UNIROUEN, Laboratoire Glyco-MEV EA4358, Normandie Université, Rouen, France
| | - Julie Hardouin
- UNIROUEN, PISSARO Proteomic Facility, Institute for Research and Innovation in Biomedicine, Normandie Université, Mont-Saint-Aignan, France
- Normandie University, UNIROUEN, INSERM US 51, CNRS UAR 2026, HeRacLeS-PISSARO, Rouen, France
- Polymers, Biopolymers, Surface Laboratory, UMR 6270 CNRS, University of Rouen, Mont-Saint-Aignan, France
| | - Bruno Gügi
- UNIROUEN, Laboratoire Glyco-MEV EA4358, Normandie Université, Rouen, France
| | - Muriel Bardor
- UNIROUEN, Laboratoire Glyco-MEV EA4358, Normandie Université, Rouen, France
- Institut Universitaire de France, Paris, France
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36
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Camoying MG, Thoms S, Geuer JK, Koch BP, Bischof K, Trimborn S. In contrast to diatoms, cryptophytes are susceptible to iron limitation, but not to ocean acidification. PHYSIOLOGIA PLANTARUM 2022; 174:e13614. [PMID: 35199361 DOI: 10.1111/ppl.13614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 12/09/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
Previous field studies in the Southern Ocean (SO) indicated an increased occurrence and dominance of cryptophytes over diatoms due to climate change. To gain a better mechanistic understanding of how the two ecologically important SO phytoplankton groups cope with ocean acidification (OA) and iron (Fe) availability, we chose two common representatives of Antarctic waters, the cryptophyte Geminigera cryophila and the diatom Pseudo-nitzschia subcurvata. Both species were grown at 2°C under different pCO2 (400 vs. 900 μatm) and Fe (0.6 vs. 1.2 nM) conditions. For P. subcurvata, an additional high pCO2 level was applied (1400 μatm). At ambient pCO2 under low Fe supply, growth of G. cryophila almost stopped while it remained unaffected in P. subcurvata. Under high Fe conditions, OA was not beneficial for P. subcurvata, but stimulated growth and carbon production of G. cryophila. Under low Fe supply, P. subcurvata coped much better with OA than the cryptophyte, but invested more energy into photoacclimation. Our study reveals that Fe limitation was detrimental for the growth of G. cryophila and suppressed the positive OA effect. The diatom was efficient in coping with low Fe, but was stressed by OA while both factors together strongly impacted its growth. The distinct physiological response of both species to OA and Fe limitation explains their occurrence in the field. Based on our results, Fe availability is an important modulator of OA effects on SO phytoplankton, with different implications on the occurrence of cryptophytes and diatoms in the future.
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Affiliation(s)
- Marianne G Camoying
- Ecological Chemistry, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Silke Thoms
- Ecological Chemistry, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Jana K Geuer
- Ecological Chemistry, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Boris P Koch
- Ecological Chemistry, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Department of Technology, University of Applied Sciences Bremerhaven, Bremerhaven, Germany
| | - Kai Bischof
- Marine Botany & MARUM, University of Bremen, Bremen, Germany
| | - Scarlett Trimborn
- Ecological Chemistry, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Marine Botany & MARUM, University of Bremen, Bremen, Germany
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37
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Buck JM, Wünsch M, Schober AF, Kroth PG, Lepetit B. Impact of Lhcx2 on Acclimation to Low Iron Conditions in the Diatom Phaeodactylum tricornutum. FRONTIERS IN PLANT SCIENCE 2022; 13:841058. [PMID: 35371185 PMCID: PMC8967352 DOI: 10.3389/fpls.2022.841058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 01/24/2022] [Indexed: 05/09/2023]
Abstract
Iron is a cofactor of photosystems and electron carriers in the photosynthetic electron transport chain. Low concentrations of dissolved iron are, therefore, the predominant factor that limits the growth of phototrophs in large parts of the open sea like the Southern Ocean and the North Pacific, resulting in "high nutrient-low chlorophyll" (HNLC) areas. Diatoms are among the most abundant microalgae in HNLC zones. Besides efficient iron uptake mechanisms, efficient photoprotection might be one of the key traits enabling them to outcompete other algae in HNLC regions. In diatoms, Lhcx proteins play a crucial role in one of the main photoprotective mechanisms, the energy-dependent fluorescence quenching (qE). The expression of Lhcx proteins is strongly influenced by various environmental triggers. We show that Lhcx2 responds specifically and in a very sensitive manner to iron limitation in the diatom Phaeodactylum tricornutum on the same timescale as the known iron-regulated genes ISIP1 and CCHH11. By comparing Lhcx2 knockout lines with wild type cells, we reveal that a strongly increased qE under iron limitation is based on the upregulation of Lhcx2. Other observed iron acclimation phenotypes in P. tricornutum include a massively reduced chlorophyll a content/cell, a changed ratio of light harvesting and photoprotective pigments per chlorophyll a, a decreased amount of photosystem II and photosystem I cores, an increased functional photosystem II absorption cross section, and decoupled antenna complexes. H2O2 formation at photosystem I induced by high light is lowered in iron-limited cells, while the amount of total reactive oxygen species is rather increased. Our data indicate a possible reduction in singlet oxygen by Lhcx2-based qE, while the other iron acclimation phenotype parameters monitored are not affected by the amount of Lhcx2 and qE.
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Hippmann AA, Schuback N, Moon K, McCrow JP, Allen AE, Foster LF, Green BR, Maldonado MT. Proteomic analysis of metabolic pathways supports chloroplast-mitochondria cross-talk in a Cu-limited diatom. PLANT DIRECT 2022; 6:e376. [PMID: 35079683 PMCID: PMC8777261 DOI: 10.1002/pld3.376] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 12/09/2021] [Accepted: 12/11/2021] [Indexed: 05/19/2023]
Abstract
Diatoms are one of the most successful phytoplankton groups in our oceans, being responsible for over 20% of the Earth's photosynthetic productivity. Their chimeric genomes have genes derived from red algae, green algae, bacteria, and heterotrophs, resulting in multiple isoenzymes targeted to different cellular compartments with the potential for differential regulation under nutrient limitation. The resulting interactions between metabolic pathways are not yet fully understood. We previously showed how acclimation to Cu limitation enhanced susceptibility to overreduction of the photosynthetic electron transport chain and its reorganization to favor photoprotection over light harvesting in the oceanic diatom Thalassiosira oceanica (Hippmann et al., 2017, 10.1371/journal.pone.0181753). In order to gain a better understanding of the overall metabolic changes that help alleviate the stress of Cu limitation, we have further analyzed the comprehensive proteomic datasets generated in that study to identify differentially expressed proteins involved in carbon, nitrogen, and oxidative stress-related metabolic pathways. Metabolic pathway analysis showed integrated responses to Cu limitation. The upregulation of ferredoxin (Fdx) was correlated with upregulation of plastidial Fdx-dependent isoenzymes involved in nitrogen assimilation as well as enzymes involved in glutathione synthesis, thus suggesting an integration of nitrogen uptake and metabolism with photosynthesis and oxidative stress resistance. The differential expression of glycolytic isoenzymes located in the chloroplast and mitochondria may enable them to channel both excess electrons and/or ATP between these compartments. An additional support for chloroplast-mitochondrial cross-talk is the increased expression of chloroplast and mitochondrial proteins involved in the proposed malate shunt under Cu limitation.
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Affiliation(s)
- Anna A. Hippmann
- Department of Earth Ocean and Atmospheric ScienceUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Nina Schuback
- Department of Earth Ocean and Atmospheric ScienceUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Kyung‐Mee Moon
- Biochemistry and Molecular BiologyMichael Smith LaboratoriesVancouverBritish ColumbiaCanada
| | - John P. McCrow
- Microbial and Environmental GenomicsJ. Craig Venter InstituteLa JollaCAUSA
| | - Andrew E. Allen
- Microbial and Environmental GenomicsJ. Craig Venter InstituteLa JollaCAUSA
- Scripps Institution of OceanographyUniversity of CaliforniaSan DiegoCAUSA
| | - Leonard F. Foster
- Biochemistry and Molecular BiologyMichael Smith LaboratoriesVancouverBritish ColumbiaCanada
| | - Beverley R. Green
- Department of BotanyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
| | - Maria T. Maldonado
- Department of Earth Ocean and Atmospheric ScienceUniversity of British ColumbiaVancouverBritish ColumbiaCanada
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Malych R, Stopka P, Mach J, Kotabová E, Prášil O, Sutak R. Flow cytometry-based study of model marine microalgal consortia revealed an ecological advantage of siderophore utilization by the dinoflagellate Amphidinium carterae. Comput Struct Biotechnol J 2021; 20:287-295. [PMID: 35024100 PMCID: PMC8718654 DOI: 10.1016/j.csbj.2021.12.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 11/09/2022] Open
Abstract
Investigations of phytoplankton responses to iron stress in seawater are complicated by the fact that iron concentrations do not necessarily reflect bioavailability. Most studies to date have been based on single species or field samples and are problematic to interpret. Here, we report results from an experimental cocultivation model system that enabled us to evaluate interspecific competition as a function of iron content and form, and to study the effect of nutritional conditions on the proteomic profiles of individual species. Our study revealed that the dinoflagellate Amphidinium carterae was able to utilize iron from a hydroxamate siderophore, a strategy that could provide an ecological advantage in environments where siderophores present an important source of iron. Additionally, proteomic analysis allowed us to identify a potential candidate protein involved in iron acquisition from hydroxamate siderophores, a strategy that is largely unknown in eukaryotic phytoplankton.
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Key Words
- (s)PLS-DA, (sparse) partial least squares discriminant analysis
- AUC, area under curve
- Amphidinium carterae
- AtpE, ATP synthase
- BCS, bathocuproinedisulfonic acid disodium salt
- CREG1, cellular repressor of E1A stimulated genes 1
- DFOB, desferrioxamine B
- EDTA, ethylenediaminetetraacetic acid
- ENT, enterobactin
- FACS, fluorescence-activated cell sorting
- FBAI, fructose-bisphosphate aldolase I
- FBAII, fructose-bisphosphate aldolase II
- FBP1, putative ferrichrome-binding protein
- FOB, ferrioxamine B
- Flow cytometry
- ISIP, iron starvation induced protein
- Iron
- LHCX, light-harvesting complex subunits
- LL, long-term iron limitation
- LR, iron enrichment
- Marine microalgae
- NBD, nitrobenz-2-oxa-1,3-diazole
- NPQ, nonphotochemical quenching
- PAGE, polyacrylamide gel electrophoresis
- PSI, photosystem I
- PSII, photosystem II
- PetA, cytochrome b6/f
- Proteomics
- PsaC, photosystem I iron-sulfur center
- PsaD, photosystem I reaction center subunit II
- PsaE, photosystem I reaction center subunit IV
- PsaL, photosystem I reaction center subunit XI
- PsbC, photosystem II CP43 reaction center protein
- PsbV, cytochrome c-550
- RR, long-term iron sufficiency
- SOD1, superoxide dismutase [Cu-Zn]
- Siderophores
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Affiliation(s)
- Ronald Malych
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech
| | - Pavel Stopka
- Department of Zoology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech
| | - Jan Mach
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech
| | - Eva Kotabová
- Institute of Microbiology, Academy of Sciences, Centrum Algatech, Trebon, Czech
| | - Ondřej Prášil
- Institute of Microbiology, Academy of Sciences, Centrum Algatech, Trebon, Czech
| | - Robert Sutak
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Vestec, Czech
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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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Liu X, Xie X, Gao S, Wang L, Zhou L, Liu Y, Hu Q, Gu W, Wang G. Chlorophyll fluorescence as a light signal enhances iron uptake by the marine diatom Phaeodactylum tricornutum under high-cell density conditions. BMC Biol 2021; 19:249. [PMID: 34814917 PMCID: PMC8609858 DOI: 10.1186/s12915-021-01177-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 10/28/2021] [Indexed: 11/10/2022] Open
Abstract
Background Diatoms usually dominate phytoplankton blooms in open oceans, exhibiting extremely high population densities. Although the iron uptake rate of diatoms largely determines the magnitude and longevity of diatom blooms, the underlying mechanisms regulating iron uptake remain unclear. Results The transcription of two iron uptake proteins, ISIP2a and ISIP1, in the marine diatom Phaeodactylum tricornutum was enhanced with increasing cell density, whereas the cellular iron content showed the opposite trend. When compared with the wild-type strain, knockdown of ISIP2a resulted in 43% decrease in cellular iron content, implying the involvement of ISIP2a in iron uptake under high-cell density conditions. Incubation of the diatom cells with sonicated cell lysate conditioned by different cell densities did not affect ISIP2a and ISIP1 expression, ruling out regulation via chemical cues. In contrast, ISIP2a and ISIP1 transcription were strongly induced by red light. Besides, chlorophyll fluorescence excited from the blue light was also positively correlated with population density. Subsequently, a “sandwich” illumination incubator was designed to filter out stray light and ensure that the inner layer cells only receive the emitted chlorophyll fluorescence from outer layers, and the results showed that the increase in outer cell density significantly elevated ISIP2a and ISIP1 transcription in inner layer cells. In situ evidence from Tara oceans also showed positively correlated between diatom ISIP transcripts and chlorophyll content. Conclusions This study shows that chlorophyll fluorescence derived from neighboring cells is able to upregulate ISIP2a and ISIP1 expression to facilitate iron assimilation under high-cell density. These results provide novel insights into biotic signal sensing in phytoplankton, which can help to elucidate the underlying mechanisms of marine diatom blooms. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01177-z.
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Affiliation(s)
- Xuehua Liu
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,College of Earth Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Xiujun Xie
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Shan Gao
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Lepu Wang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,College of Earth Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Lu Zhou
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,College of Earth Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yao Liu
- Public Technology Service Center, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Qiang Hu
- Institute for Advanced Study, Shenzhen University, Shenzhen, China
| | - Wenhui Gu
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China. .,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
| | - Guangce Wang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China. .,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
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Phytate as a phosphorus nutrient with impacts on iron stress-related gene expression for phytoplankton: insights from diatom Phaeodactylum tricornutum. Appl Environ Microbiol 2021; 88:e0209721. [PMID: 34757820 DOI: 10.1128/aem.02097-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phytoplankton have evolved a capability to acquire phosphorus (P) from dissolved organic phosphorus (DOP) since the preferred form, dissolved inorganic phosphate (DIP, or Pi), is often limited in parts of the ocean. Phytic acid (PA) is abundantly synthesized in plants and rich in excreta of animals, potentially enriching the DOP pool in coastal oceans. However, whether and how PA may be used by phytoplankton are poorly understood. Here, we investigated PA utilization and underlying metabolic pathways in the diatom model Phaeodactylum tricornutum. The physiological results showed that P. tricornutum could utilize PA as a sole source of P nutrient to support growth. Meanwhile, the replacement of PA for DIP also caused changes in multiple cellular processes such as inositol phosphate metabolism, photosynthesis, and signal transduction. These results suggest that PA is bioavailable to P. tricornutum and can directly participate the metabolic pathways of PA-grown cells. However, our data showed that the utilization of PA was markedly less efficient than that of DIP, and PA-grown cells exhibited P and iron (Fe) nutrient stress signals. Implicated in these findings is the potential of complicated responses of phytoplankton to an ambient DOP species, which calls for more systematic investigation. IMPORTANCE PA is abundant in plants, and cannot be digested by non-ruminant animals. Hence, it is potentially a significant component of the DOP pool in the coastal waters. Despite the potential importance, there is little information about its bioavailability to phytoplankton as a source of P nutrient and if so what molecular mechanisms are involved. In this study, we found that part of PA could be utilized by the diatom P. tricornutum to support growth, and another portion of PA can act as a substrate directly participating in various metabolism pathways and cellular processes. However, our physiological and transcriptomic data show that PA-grown cells still exhibited signs of P stress and potential Fe stress. These results have significant implications in phytoplankton P nutrient ecology and provide a novel insight into multi-faceted impacts of DOP utilization on phytoplankton nutrition and metabolism.
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Gain G, Vega de Luna F, Cordoba J, Perez E, Degand H, Morsomme P, Thiry M, Baurain D, Pierangelini M, Cardol P. Trophic state alters the mechanism whereby energetic coupling between photosynthesis and respiration occurs in Euglena gracilis. THE NEW PHYTOLOGIST 2021; 232:1603-1617. [PMID: 34392544 PMCID: PMC9292222 DOI: 10.1111/nph.17677] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 08/06/2021] [Indexed: 06/13/2023]
Abstract
The coupling between mitochondrial respiration and photosynthesis plays an important role in the energetic physiology of green plants and some secondary-red photosynthetic eukaryotes (diatoms), allowing an efficient CO2 assimilation and optimal growth. Using the flagellate Euglena gracilis, we first tested if photosynthesis-respiration coupling occurs in this species harbouring secondary green plastids (i.e. originated from an endosymbiosis between a green alga and a phagotrophic euglenozoan). Second, we tested how the trophic state (mixotrophy and photoautotrophy) of the cell alters the mechanisms involved in the photosynthesis-respiration coupling. Energetic coupling between photosynthesis and respiration was determined by testing the effect of respiratory inhibitors on photosynthesis, and measuring the simultaneous variation of photosynthesis and respiration rates as a function of temperature (i.e. thermal response curves). The mechanism involved in the photosynthesis-respiration coupling was assessed by combining proteomics, biophysical and cytological analyses. Our work shows that there is photosynthesis-respiration coupling and membrane contacts between mitochondria and chloroplasts in E. gracilis. However, whereas in mixotrophy adjustment of the chloroplast ATP/NADPH ratio drives the interaction, in photoautotrophy the coupling is conditioned by CO2 limitation and photorespiration. This indicates that maintenance of photosynthesis-respiration coupling, through plastic metabolic responses, is key to E. gracilis functioning under changing environmental conditions.
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Affiliation(s)
- Gwenaëlle Gain
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
| | - Félix Vega de Luna
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
| | - Javier Cordoba
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
| | - Emilie Perez
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
| | - Hervé Degand
- Louvain Institute of Biomolecular Science and Technology (LIBST)UCLouvainLouvain‐la‐NeuveB‐1348Belgium
| | - Pierre Morsomme
- Louvain Institute of Biomolecular Science and Technology (LIBST)UCLouvainLouvain‐la‐NeuveB‐1348Belgium
| | - Marc Thiry
- Laboratoire de Biologie Cellulaire et TissulaireGiga‐NeurosciencesULiègeLiègeB‐4000Belgium
| | - Denis Baurain
- InBioS – PhytoSYSTEMSEukaryotic PhylogenomicsULiègeLiègeB‐4000Belgium
| | - Mattia Pierangelini
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
| | - Pierre Cardol
- InBioS – PhytoSYSTEMSLaboratoire de Génétique et Physiologie des MicroalguesULiègeLiègeB‐4000Belgium
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Roca M, Pérez-Gálvez A. Metabolomics of Chlorophylls and Carotenoids: Analytical Methods and Metabolome-Based Studies. Antioxidants (Basel) 2021; 10:1622. [PMID: 34679756 PMCID: PMC8533378 DOI: 10.3390/antiox10101622] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 10/03/2021] [Accepted: 10/12/2021] [Indexed: 01/27/2023] Open
Abstract
Chlorophylls and carotenoids are two families of antioxidants present in daily ingested foods, whose recognition as added-value ingredients runs in parallel with the increasing number of demonstrated functional properties. Both groups include a complex and vast number of compounds, and extraction and analysis methods evolved recently to a modern protocol. New methodologies are more potent, precise, and accurate, but their application requires a better understanding of the technical and biological context. Therefore, the present review compiles the basic knowledge and recent advances of the metabolomics of chlorophylls and carotenoids, including the interrelation with the primary metabolism. The study includes material preparation and extraction protocols, the instrumental techniques for the acquisition of spectroscopic and spectrometric properties, the workflows and software tools for data pre-processing and analysis, and the application of mass spectrometry to pigment metabolomics. In addition, the review encompasses a critical description of studies where metabolomics analyses of chlorophylls and carotenoids were developed as an approach to analyzing the effects of biotic and abiotic stressors on living organisms.
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Affiliation(s)
| | - Antonio Pérez-Gálvez
- Food Phytochemistry Department, Instituto de la Grasa (CSIC), Building 46, 41013 Sevilla, Spain;
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Shaked Y, Twining BS, Tagliabue A, Maldonado MT. Probing the Bioavailability of Dissolved Iron to Marine Eukaryotic Phytoplankton Using In Situ Single Cell Iron Quotas. GLOBAL BIOGEOCHEMICAL CYCLES 2021; 35:e2021GB006979. [PMID: 35865367 PMCID: PMC9286392 DOI: 10.1029/2021gb006979] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 06/09/2021] [Accepted: 06/29/2021] [Indexed: 05/08/2023]
Abstract
We present a new approach for quantifying the bioavailability of dissolved iron (dFe) to oceanic phytoplankton. Bioavailability is defined using an uptake rate constant (kin-app) computed by combining data on: (a) Fe content of individual in situ phytoplankton cells; (b) concurrently determined seawater dFe concentrations; and (c) growth rates estimated from the PISCES model. We examined 930 phytoplankton cells, collected between 2002 and 2016 from 45 surface stations during 11 research cruises. This approach is only valid for cells that have upregulated their high-affinity Fe uptake system, so data were screened, yielding 560 single cell k in-app values from 31 low-Fe stations. We normalized k in-app to cell surface area (S.A.) to account for cell-size differences. The resulting bioavailability proxy (k in-app/S.A.) varies among cells, but all values are within bioavailability limits predicted from defined Fe complexes. In situ dFe bioavailability is higher than model Fe-siderophore complexes and often approaches that of highly available inorganic Fe'. Station averaged k in-app/S.A. are also variable but show no systematic changes across location, temperature, dFe, and phytoplankton taxa. Given the relative consistency of k in-app/S.A. among stations (ca. five-fold variation), we computed a grand-averaged dFe availability, which upon normalization to cell carbon (C) yields k in-app/C of 42,200 ± 11,000 L mol C-1 d-1. We utilize k in-app/C to calculate dFe uptake rates and residence times in low Fe oceanic regions. Finally, we demonstrate the applicability of k in-app/C for constraining Fe uptake rates in earth system models, such as those predicting climate mediated changes in net primary production in the Fe-limited Equatorial Pacific.
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Affiliation(s)
- Yeala Shaked
- Freddy and Nadine Herrmann Institute of Earth SciencesHebrew UniversityJerusalemIsrael
- Interuniversity Institute for Marine SciencesEilatIsrael
| | | | | | - Maria T. Maldonado
- Department of Earth, Ocean and Atmospheric SciencesUniversity of British ColumbiaVancouverCanada
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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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Shire DM, Kustka AB. Proteomic responses of the coccolithophore Emiliania huxleyi to zinc limitation and trace metal substitution. Environ Microbiol 2021; 24:819-834. [PMID: 34139058 DOI: 10.1111/1462-2920.15644] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/26/2021] [Accepted: 06/15/2021] [Indexed: 11/30/2022]
Abstract
Zinc concentrations in pelagic surface waters are within the range that limits growth in marine phytoplankton cultures. However, the influence of zinc on marine primary production and phytoplankton communities is not straightforward due to largely uncharacterized abilities for some phytoplankton to access zinc species that may not be universally bioavailable and substitute zinc with cobalt or cadmium. We used a quantitative proteomic approach to investigate these strategies and other responses to zinc limitation in the coccolithophore Emiliania huxleyi, a dominant species in low zinc waters. Zinc limitation resulted in the upregulation of metal transport proteins (ZIP, TroA-like) and COG0523 metallochaperones. Some proteins were uniquely sensitive to growth under replete zinc, substitution of zinc with cobalt, or enhancement of growth with cadmium, and may be useful as biomarkers of zinc stress or substitution in situ. Several proteins specifically upregulated under cobalt-supported or cadmium-enhanced growth appear to reflect stress responses, despite titration of these metals to optimal nutritive levels. Relief from zinc limitation by zinc or cadmium resulted in increased expression of a δ-carbonic anhydrase. Our inability to detect metal binding enzymes that are specifically induced under cobalt- or cadmium-supported growth suggests cambialism is important for zinc substitution in E. huxleyi.
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Affiliation(s)
- David M Shire
- Department of Earth and Environmental Science, Rutgers University-Newark, Newark, NJ, USA
| | - Adam B Kustka
- Department of Earth and Environmental Science, Rutgers University-Newark, Newark, NJ, USA
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48
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Zhen ZH, Qin S, Ren QM, Wang Y, Ma YY, Wang YC. Reciprocal Effect of Copper and Iron Regulation on the Proteome of Synechocystis sp. PCC 6803. Front Bioeng Biotechnol 2021; 9:673402. [PMID: 34041232 PMCID: PMC8141849 DOI: 10.3389/fbioe.2021.673402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 04/14/2021] [Indexed: 11/13/2022] Open
Abstract
Cyanobacteria can acclimate to changing copper and iron concentrations in the environment via metal homeostasis, but a general mechanism for interpreting their dynamic relationships is sparse. In this study, we assessed growth and chlorophyll fluorescence of Synechocystis sp. PCC 6803 and investigated proteomic responses to copper and iron deductions. Results showed that copper and iron exerted reciprocal effect on the growth and photosynthesis of Synechocystis sp. PCC 6803 at combinations of different concentrations. And some proteins involved in the uptake of copper and iron and the photosynthetic electron transport system exhibit Cu-Fe proteomic association. The protein abundance under copper and iron deduction affected the photosynthetic electronic activity of Synechocystis sp. PCC 6803 and eventually affected the growth and photosynthesis. Based on these results, we hypothesize that the Cu-Fe proteomic association of Synechocystis sp. PCC 6803 can be elucidated via the uptake system of outer membrane-periplasmic space-inner plasma membrane-thylakoid membrane, and this association is mainly required to maintain electron transfer. This study provides a broader view regarding the proteomic association between Cu and Fe in cyanobacteria, which will shed light on the role of these two metal elements in cyanobacterial energy metabolism and biomass accumulation.
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Affiliation(s)
- Zhang-He Zhen
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Song Qin
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Qing-Min Ren
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yu Wang
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
| | - Yu-Ying Ma
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
| | - Yin-Chu Wang
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
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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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50
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Shafiee RT, Snow JT, Hester S, Zhang Q, Rickaby REM. Proteomic response of the marine ammonia-oxidising archaeon Nitrosopumilus maritimus to iron limitation reveals strategies to compensate for nutrient scarcity. Environ Microbiol 2021; 24:835-849. [PMID: 33876540 DOI: 10.1111/1462-2920.15491] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 03/25/2021] [Indexed: 11/26/2022]
Abstract
Dissolved iron (Fe) is vanishingly low in the oceans, with ecological success conferred to microorganisms that can restructure their biochemistry to maintain high growth rates during Fe scarcity. Chemolithoautotrophic ammonia-oxidising archaea (AOA) are highly abundant in the oceans, constituting ~30% of cells below the photic zone. Here we examine the proteomic response of the AOA isolate Nitrosopumilus maritimus to growth-limiting Fe concentrations. Under Fe limitation, we observed a significant reduction in the intensity of Fe-dense ferredoxins associated with respiratory complex I whilst complex III and IV proteins with more central roles in the electron transport chain remain unchanged. We concomitantly observed an increase in the intensity of Fe-free functional alternatives such as flavodoxin and plastocyanin, thioredoxin and alkyl hydroperoxide which are known to mediate electron transport and reactive oxygen species detoxification, respectively. Under Fe limitation, we found a marked increase in the intensity of the ABC phosphonate transport system (Phn), highlighting an intriguing link between Fe and P cycling in N. maritimus. We hypothesise that an elevated uptake of exogenous phosphonates under Fe limitation may either supplement N. maritimus' endogenous methylphosphonate biosynthesis pathway - which requires Fe - or enhance the production of phosphonate-containing exopolysaccharides known to efficiently bind environmental Fe.
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Affiliation(s)
- Roxana T Shafiee
- Department of Earth Sciences, South Parks Road, University of Oxford, Oxfordshire, OX1 3AN, UK
| | - Joseph T Snow
- Department of Earth Sciences, South Parks Road, University of Oxford, Oxfordshire, OX1 3AN, UK
| | - Svenja Hester
- Department of Biochemistry, South Parks Road, University of Oxford, Oxfordshire, OX1 3QU, UK
| | - Qiong Zhang
- Department of Earth Sciences, South Parks Road, University of Oxford, Oxfordshire, OX1 3AN, UK
| | - Rosalind E M Rickaby
- Department of Earth Sciences, South Parks Road, University of Oxford, Oxfordshire, OX1 3AN, UK
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