1
|
Grypioti E, Richard H, Kryovrysanaki N, Jaubert M, Falciatore A, Verret F, Kalantidis K. Dicer-dependent heterochromatic small RNAs in the model diatom species Phaeodactylum tricornutum. New Phytol 2024; 241:811-826. [PMID: 38044751 DOI: 10.1111/nph.19429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 10/17/2023] [Indexed: 12/05/2023]
Abstract
Diatoms are eukaryotic microalgae responsible for nearly half of the marine productivity. RNA interference (RNAi) is a mechanism of regulation of gene expression mediated by small RNAs (sRNAs) processed by the endoribonuclease Dicer (DCR). To date, the mechanism and physiological role of RNAi in diatoms are unknown. We mined diatom genomes and transcriptomes for key RNAi effectors and retraced their phylogenetic history. We generated DCR knockout lines in the model diatom species Phaeodactylum tricornutum and analyzed their mRNA and sRNA populations, repression-associated histone marks, and acclimatory response to nitrogen starvation. Diatoms presented a diversification of key RNAi effectors whose distribution across species suggests the presence of distinct RNAi pathways. P. tricornutum DCR was found to process 26-31-nt-long double-stranded sRNAs originating mostly from transposons covered by repression-associated epigenetic marks. In parallel, P. tricornutum DCR was necessary for the maintenance of the repression-associated histone marks H3K9me2/3 and H3K27me3. Finally, PtDCR-KO lines presented a compromised recovery post nitrogen starvation suggesting a role for P. tricornutum DCR in the acclimation to nutrient stress. Our study characterized the molecular function of the single DCR homolog of P. tricornutum suggesting an association between RNAi and heterochromatin maintenance in this model diatom species.
Collapse
Affiliation(s)
- Emilia Grypioti
- Department of Biology, University of Crete, PO Box 2208, 70013, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013, Heraklion, Crete, Greece
- Institute of Marine Biology and Aquaculture, Hellenic Center for Marine Research, 71500, Gournes, Crete, Greece
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR 7238 Sorbonne Université, 75005, Paris, France
| | - Hugues Richard
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR 7238 Sorbonne Université, 75005, Paris, France
- Bioinformatics Unit, Genome Competence Center (MF1), Robert Koch Institute, 13353, Berlin, Germany
| | - Nikoleta Kryovrysanaki
- Department of Biology, University of Crete, PO Box 2208, 70013, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013, Heraklion, Crete, Greece
| | - Marianne Jaubert
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR 7238 Sorbonne Université, 75005, Paris, France
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005, Paris, France
| | - Angela Falciatore
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR 7238 Sorbonne Université, 75005, Paris, France
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005, Paris, France
| | - Frédéric Verret
- Department of Biology, University of Crete, PO Box 2208, 70013, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013, Heraklion, Crete, Greece
- Institute of Marine Biology and Aquaculture, Hellenic Center for Marine Research, 71500, Gournes, Crete, Greece
| | - Kriton Kalantidis
- Department of Biology, University of Crete, PO Box 2208, 70013, Heraklion, Crete, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013, Heraklion, Crete, Greece
| |
Collapse
|
2
|
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. J Phycol 2023; 59:1114-1122. [PMID: 37975560 DOI: 10.1111/jpy.13400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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.
Collapse
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
| |
Collapse
|
3
|
Abstract
The regular movements of waves and tides are obvious representations of the oceans' rhythmicity. But the rhythms of marine life span across ecological niches and timescales, including short (in the range of hours) and long (in the range of days and months) periods. These rhythms regulate the physiology and behavior of individuals, as well as their interactions with each other and with the environment. This review highlights examples of rhythmicity in marine animals and algae that represent important groups of marine life across different habitats. The examples cover ecologically highly relevant species and a growing number of laboratory model systems that are used to disentangle key mechanistic principles. The review introduces fundamental concepts of chronobiology, such as the distinction between rhythmic and endogenous oscillator-driven processes. It also addresses the relevance of studying diverse rhythms and oscillators, as well as their interconnection, for making better predictions of how species will respond to environmental perturbations, including climate change. As the review aims to address scientists from the diverse fields of marine biology, ecology, and molecular chronobiology, all of which have their own scientific terms, we provide definitions of key terms throughout the article.
Collapse
Affiliation(s)
- N Sören Häfker
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria; ,
- Research Platform "Rhythms of Life," University of Vienna, Vienna BioCenter, Vienna, Austria
| | - Gabriele Andreatta
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria; ,
- Research Platform "Rhythms of Life," University of Vienna, Vienna BioCenter, Vienna, Austria
| | - Alessandro Manzotti
- Laboratoire de Biologie du Chloroplaste et Perception de la Lumière chez les Microalgues, UMR 7141, CNRS, Sorbonne Université, Institut de Biologie Physico-Chimique, Paris, France;
| | - Angela Falciatore
- Laboratoire de Biologie du Chloroplaste et Perception de la Lumière chez les Microalgues, UMR 7141, CNRS, Sorbonne Université, Institut de Biologie Physico-Chimique, Paris, France;
| | - Florian Raible
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria; ,
- Research Platform "Rhythms of Life," University of Vienna, Vienna BioCenter, Vienna, Austria
| | - Kristin Tessmar-Raible
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria; ,
- Research Platform "Rhythms of Life," University of Vienna, Vienna BioCenter, Vienna, Austria
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
| |
Collapse
|
4
|
Falciatore A, Bailleul B, Boulouis A, Bouly JP, Bujaldon S, Cheminant-Navarro S, Choquet Y, de Vitry C, Eberhard S, Jaubert M, Kuras R, Lafontaine I, Landier S, Selles J, Vallon O, Wostrikoff K. Light-driven processes: key players of the functional biodiversity in microalgae. C R Biol 2022; 345:15-38. [PMID: 36847462 DOI: 10.5802/crbiol.80] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 07/11/2022] [Indexed: 11/24/2022]
Abstract
Microalgae are prominent aquatic organisms, responsible for about half of the photosynthetic activity on Earth. Over the past two decades, breakthroughs in genomics and ecosystem biology, as well as the development of genetic resources in model species, have redrawn the boundaries of our knowledge on the relevance of these microbes in global ecosystems. However, considering their vast biodiversity and complex evolutionary history, our comprehension of algal biology remains limited. As algae rely on light, both as their main source of energy and for information about their environment, we focus here on photosynthesis, photoperception, and chloroplast biogenesis in the green alga Chlamydomonas reinhardtii and marine diatoms. We describe how the studies of light-driven processes are key to assessing functional biodiversity in evolutionary distant microalgae. We also emphasize that integration of laboratory and environmental studies, and dialogues between different scientific communities are both timely and essential to understand the life of phototrophs in complex ecosystems and to properly assess the consequences of environmental changes on aquatic environments globally.
Collapse
|
5
|
Vicedomini R, Bouly JP, Laine E, Falciatore A, Carbone A. Multiple profile models extract features from protein sequence data and resolve functional diversity of very different protein families. Mol Biol Evol 2022; 39:6556147. [PMID: 35353898 PMCID: PMC9016551 DOI: 10.1093/molbev/msac070] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Functional classification of proteins from sequences alone has become a critical bottleneck in understanding the myriad of protein sequences that accumulate in our databases. The great diversity of homologous sequences hides, in many cases, a variety of functional activities that cannot be anticipated. Their identification appears critical for a fundamental understanding of the evolution of living organisms and for biotechnological applications. ProfileView is a sequence-based computational method, designed to functionally classify sets of homologous sequences. It relies on two main ideas: the use of multiple profile models whose construction explores evolutionary information in available databases, and a novel definition of a representation space in which to analyse sequences with multiple profile models combined together. ProfileView classifies protein families by enriching known functional groups with new sequences and discovering new groups and subgroups. We validate ProfileView on seven classes of widespread proteins involved in the interaction with nucleic acids, amino acids and small molecules, and in a large variety of functions and enzymatic reactions. Profile-View agrees with the large set of functional data collected for these proteins from the literature regarding the organisation into functional subgroups and residues that characterise the functions. In addition, ProfileView resolves undefined functional classifications and extracts the molecular determinants underlying protein functional diversity, showing its potential to select sequences towards accurate experimental design and discovery of novel biological functions. On protein families with complex domain architecture, ProfileView functional classification reconciles domain combinations, unlike phylogenetic reconstruction. ProfileView proves to outperform the functional classification approach PANTHER, the two k-mer based methods CUPP and eCAMI and a neural network approach based on Restricted Boltzmann Machines. It overcomes time complexity limitations of the latter.
Collapse
Affiliation(s)
- R Vicedomini
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative - UMR 7238, 4 place Jussieu, 75005 Paris, France.,Sorbonne Université, Institut des Sciences du Calcul et des Données
| | - J P Bouly
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative - UMR 7238, 4 place Jussieu, 75005 Paris, France.,CNRS, Sorbonne Université Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae - UMR7141, Paris, France
| | - E Laine
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative - UMR 7238, 4 place Jussieu, 75005 Paris, France
| | - A Falciatore
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative - UMR 7238, 4 place Jussieu, 75005 Paris, France.,CNRS, Sorbonne Université Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae - UMR7141, Paris, France
| | - A Carbone
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative - UMR 7238, 4 place Jussieu, 75005 Paris, France.,Institut Universitaire de France, Paris 75005, France
| |
Collapse
|
6
|
Giovagnetti V, Jaubert M, Shukla MK, Ungerer P, Bouly JP, Falciatore A, Ruban AV. Biochemical and molecular properties of LHCX1, the essential regulator of dynamic photoprotection in diatoms. Plant Physiol 2022; 188:509-525. [PMID: 34595530 PMCID: PMC8774712 DOI: 10.1093/plphys/kiab425] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 08/06/2021] [Indexed: 05/24/2023]
Abstract
Light harvesting is regulated by a process triggered by the acidification of the thylakoid lumen, known as nonphotochemical "energy-dependent quenching" (qE). In diatoms, qE is controlled by the light-harvesting complex (LHC) protein LHCX1, while the LHC stress-related (LHCSR) and photosystem II subunit S proteins are essential for green algae and plants, respectively. Here, we report a biochemical and molecular characterization of LHCX1 to investigate its role in qE. We found that, when grown under intermittent light, Phaeodactylum tricornutum forms very large qE, due to LHCX1 constitutive upregulation. This "super qE" is abolished in LHCX1 knockout mutants. Biochemical and spectroscopic analyses of LHCX1 reveal that this protein might differ in the character of binding pigments relative to the major pool of light-harvesting antenna proteins. The possibility of transient pigment binding or not binding pigments at all is discussed. Targeted mutagenesis of putative protonatable residues (D95 and E205) in transgenic P. tricornutum lines does not alter qE capacity, showing that they are not involved in sensing lumen pH, differently from residues conserved in LHCSR3. Our results suggest functional divergence between LHCX1 and LHCSR3 in qE modulation. We propose that LHCX1 evolved independently to facilitate dynamic tracking of light fluctuations in turbulent waters. The evolution of LHCX(-like) proteins in organisms with secondary red plastids, such as diatoms, might have conferred a selective advantage in the control of dynamic photoprotection, ultimately resulting in their ecological success.
Collapse
Affiliation(s)
- Vasco Giovagnetti
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK
| | - Marianne Jaubert
- Laboratoire de Biologie du Chloroplaste et Perception de la Lumière Chez les Micro-algues, UMR7141, CNRS, Sorbonne Université, Institut de Biologie Physico-Chimique, Paris 75005, France
| | - Mahendra K Shukla
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK
| | - Petra Ungerer
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK
| | - Jean-Pierre Bouly
- Laboratoire de Biologie du Chloroplaste et Perception de la Lumière Chez les Micro-algues, UMR7141, CNRS, Sorbonne Université, Institut de Biologie Physico-Chimique, Paris 75005, France
| | - Angela Falciatore
- Laboratoire de Biologie du Chloroplaste et Perception de la Lumière Chez les Micro-algues, UMR7141, CNRS, Sorbonne Université, Institut de Biologie Physico-Chimique, Paris 75005, France
| | - Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK
| |
Collapse
|
7
|
Rogato A, Falciatore A. Detection and Quantification of Small Noncoding RNAs in Marine Diatoms. Methods Mol Biol 2022; 2498:315-326. [PMID: 35727553 DOI: 10.1007/978-1-0716-2313-8_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Endogenous small noncoding RNAs (sRNAs) are a large family of essential regulators of gene expression in both eukaryotes and prokaryotes. Various types of sRNAs with different size and mapping to different genome locations have been recently identified in diatoms, a successful group of phytoplankton in the marine environment. However, their biogenesis and regulatory function are still largely unknown and unexplored in these microalgae, also due to the lack of methods for their experimental analysis. Herein, we present a point-by-point description of the protocols for detection and quantification of sRNAs by Northern-blot analysis and quantitative stem-loop RT-PCR, established in the diatom molecular model specie Phaeodactylum tricornutum.
Collapse
Affiliation(s)
- Alessandra Rogato
- Institute of Biosciences and BioResources, CNR, Naples, Italy.
- Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Naples, Italy.
| | - Angela Falciatore
- Laboratoire de Biologie du chloroplaste et perception de la lumière chez les micro-algues, UMR7141, CNRS, Sorbonne Université, Institut de Biologie Physico-Chimique, Paris, France.
| |
Collapse
|
8
|
Manfellotto F, Stella GR, Falciatore A, Brunet C, Ferrante MI. Engineering the Unicellular Alga Phaeodactylum tricornutum for Enhancing Carotenoid Production. Antioxidants (Basel) 2020; 9:E757. [PMID: 32824292 PMCID: PMC7465010 DOI: 10.3390/antiox9080757] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 08/07/2020] [Accepted: 08/13/2020] [Indexed: 12/14/2022] Open
Abstract
Microalgae represent a promising resource for the production of beneficial natural compounds due to their richness in secondary metabolites and easy cultivation. Carotenoids feature among distinctive compounds of many microalgae, including diatoms, which owe their golden color to the xanthophyll fucoxanthin. Carotenoids have antioxidant, anti-obesity and anti-inflammatory properties, and there is a considerable market demand for these compounds. Here, with the aim to increase the carotenoid content in the model diatom Phaeodactylum tricornutum, we exploited genetic transformation to overexpress genes involved in the carotenoid biosynthetic pathway. We produced transgenic lines over-expressing simultaneously one, two or three carotenoid biosynthetic genes, and evaluated changes in pigment content with high-performance liquid chromatography. Two triple transformants over-expressing the genes Violaxanthin de-epoxidase (Vde), Vde-related (Vdr) and Zeaxanthin epoxidase 3 (Zep3) showed an accumulation of carotenoids, with an increase in the fucoxanthin content up to four fold. Vde, Vdr and Zep3 mRNA and protein levels in the triple transformants were coherently increased. The exact role of these enzymes in the diatom carotenoid biosynthetic pathway is not completely elucidated nevertheless our strategy successfully modulated the carotenoid metabolism leading to an accumulation of valuable compounds, leading the way toward improved utilization of microalgae in the field of antioxidants.
Collapse
Affiliation(s)
| | - Giulio Rocco Stella
- Laboratory of Computational and Quantitative Biology, UMR 7238, Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, Institut de Biologie Paris-Seine, F-75005 Paris, France; (G.R.S.); (A.F.)
- Boston Consulting Group, Via Ugo Foscolo 1, 20121 Milano, Italy
| | - Angela Falciatore
- Laboratory of Computational and Quantitative Biology, UMR 7238, Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, Institut de Biologie Paris-Seine, F-75005 Paris, France; (G.R.S.); (A.F.)
- Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR 7141, Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, Institut de Biologie Physico-Chimique, F-75005 Paris, France
| | - Christophe Brunet
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy;
| | | |
Collapse
|
9
|
Falciatore A, Jaubert M, Bouly JP, Bailleul B, Mock T. Diatom Molecular Research Comes of Age: Model Species for Studying Phytoplankton Biology and Diversity. Plant Cell 2020; 32:547-572. [PMID: 31852772 PMCID: PMC7054031 DOI: 10.1105/tpc.19.00158] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 10/18/2019] [Accepted: 12/13/2019] [Indexed: 05/08/2023]
Abstract
Diatoms are the world's most diverse group of algae, comprising at least 100,000 species. Contributing ∼20% of annual global carbon fixation, they underpin major aquatic food webs and drive global biogeochemical cycles. Over the past two decades, Thalassiosira pseudonana and Phaeodactylum tricornutum have become the most important model systems for diatom molecular research, ranging from cell biology to ecophysiology, due to their rapid growth rates, small genomes, and the cumulative wealth of associated genetic resources. To explore the evolutionary divergence of diatoms, additional model species are emerging, such as Fragilariopsis cylindrus and Pseudo-nitzschia multistriata Here, we describe how functional genomics and reverse genetics have contributed to our understanding of this important class of microalgae in the context of evolution, cell biology, and metabolic adaptations. Our review will also highlight promising areas of investigation into the diversity of these photosynthetic organisms, including the discovery of new molecular pathways governing the life of secondary plastid-bearing organisms in aquatic environments.
Collapse
Affiliation(s)
- Angela Falciatore
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005 Paris, France
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR7238 Sorbonne Université, 75005 Paris, France
| | - Marianne Jaubert
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005 Paris, France
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR7238 Sorbonne Université, 75005 Paris, France
| | - Jean-Pierre Bouly
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005 Paris, France
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR7238 Sorbonne Université, 75005 Paris, France
| | - Benjamin Bailleul
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005 Paris, France
| | - Thomas Mock
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| |
Collapse
|
10
|
Lavoie M, Saint-Béat B, Strauss J, Guérin S, Allard A, V. Hardy S, Falciatore A, Lavaud J. Genome-Scale Metabolic Reconstruction and in Silico Perturbation Analysis of the Polar Diatom Fragilariopsis cylindrus Predicts High Metabolic Robustness. Biology (Basel) 2020; 9:biology9020030. [PMID: 32079178 PMCID: PMC7168318 DOI: 10.3390/biology9020030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 01/31/2020] [Accepted: 02/08/2020] [Indexed: 12/15/2022]
Abstract
Diatoms are major primary producers in polar environments where they can actively grow under extremely variable conditions. Integrative modeling using a genome-scale model (GSM) is a powerful approach to decipher the complex interactions between components of diatom metabolism and can provide insights into metabolic mechanisms underlying their evolutionary success in polar ecosystems. We developed the first GSM for a polar diatom, Fragilariopsis cylindrus, which enabled us to study its metabolic robustness using sensitivity analysis. We find that the predicted growth rate was robust to changes in all model parameters (i.e., cell biochemical composition) except the carbon uptake rate. Constraints on total cellular carbon buffer the effect of changes in the input parameters on reaction fluxes and growth rate. We also show that single reaction deletion of 20% to 32% of active (nonzero flux) reactions and single gene deletion of 44% to 55% of genes associated with active reactions affected the growth rate, as well as the production fluxes of total protein, lipid, carbohydrate, DNA, RNA, and pigments by less than 1%, which was due to the activation of compensatory reactions (e.g., analogous enzymes and alternative pathways) with more highly connected metabolites involved in the reactions that were robust to deletion. Interestingly, including highly divergent alleles unique for F. cylindrus increased its metabolic robustness to cellular perturbations even more. Overall, our results underscore the high robustness of metabolism in F. cylindrus, a feature that likely helps to maintain cell homeostasis under polar conditions.
Collapse
Affiliation(s)
- Michel Lavoie
- Unité Mixte Internationale 3376 Takuvik, CNRS-ULaval, Département de Biologie and Québec-Océan, Université Laval, Québec, QC G1V 0A6, Canada; (B.S.-B.); (S.G.); (J.L.)
- Correspondence:
| | - Blanche Saint-Béat
- Unité Mixte Internationale 3376 Takuvik, CNRS-ULaval, Département de Biologie and Québec-Océan, Université Laval, Québec, QC G1V 0A6, Canada; (B.S.-B.); (S.G.); (J.L.)
| | - Jan Strauss
- Department of Biology, University of Hamburg, D-22607 Hamburg, Germany;
- CSSB Centre for Structural Systems Biology, c/o Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, D-22607 Hamburg, Germany
| | - Sébastien Guérin
- Unité Mixte Internationale 3376 Takuvik, CNRS-ULaval, Département de Biologie and Québec-Océan, Université Laval, Québec, QC G1V 0A6, Canada; (B.S.-B.); (S.G.); (J.L.)
| | - Antoine Allard
- Département de physique, de génie physique et d’optique, Université Laval, Québec, QC G1V 0A6, Canada;
- Centre interdisciplinaire de modélisation mathématique, Université Laval, Québec, QC G1V 0A6, Canada
| | - Simon V. Hardy
- Département d’informatique et génie logiciel, Département de biochimie, microbiologie et bio-informatique, Université Laval, Québec, QC G1V 0A6, Canada;
- Unité des Neurosciences cellulaires et moléculaires, Centre de recherche CERVO, Québec, QC G1V 0A6, Canada
| | - Angela Falciatore
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141, Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005 Paris, France;
| | - Johann Lavaud
- Unité Mixte Internationale 3376 Takuvik, CNRS-ULaval, Département de Biologie and Québec-Océan, Université Laval, Québec, QC G1V 0A6, Canada; (B.S.-B.); (S.G.); (J.L.)
| |
Collapse
|
11
|
Buck JM, Sherman J, Bártulos CR, Serif M, Halder M, Henkel J, Falciatore A, Lavaud J, Gorbunov MY, Kroth PG, Falkowski PG, Lepetit B. Lhcx proteins provide photoprotection via thermal dissipation of absorbed light in the diatom Phaeodactylum tricornutum. Nat Commun 2019; 10:4167. [PMID: 31519883 PMCID: PMC6744471 DOI: 10.1038/s41467-019-12043-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 08/16/2019] [Indexed: 11/15/2022] Open
Abstract
Diatoms possess an impressive capacity for rapidly inducible thermal dissipation of excess absorbed energy (qE), provided by the xanthophyll diatoxanthin and Lhcx proteins. By knocking out the Lhcx1 and Lhcx2 genes individually in Phaeodactylum tricornutum strain 4 and complementing the knockout lines with different Lhcx proteins, multiple mutants with varying qE capacities are obtained, ranging from zero to high values. We demonstrate that qE is entirely dependent on the concerted action of diatoxanthin and Lhcx proteins, with Lhcx1, Lhcx2 and Lhcx3 having similar functions. Moreover, we establish a clear link between Lhcx1/2/3 mediated inducible thermal energy dissipation and a reduction in the functional absorption cross-section of photosystem II. This regulation of the functional absorption cross-section can be tuned by altered Lhcx protein expression in response to environmental conditions. Our results provide a holistic understanding of the rapidly inducible thermal energy dissipation process and its mechanistic implications in diatoms. Photosynthetic organisms can dissipate excess absorbed light energy as heat to avoid photodamage. Here the authors show that induced thermal dissipation in the diatom Phaeodactylum tricornutum Pt4 is Lhcx protein-dependent and correlates with a reduced functional absorption cross-section of photosystem II.
Collapse
Affiliation(s)
- Jochen M Buck
- Plant Ecophysiology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Jonathan Sherman
- Environmental Biophysics and Molecular Ecology Program, Department of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08901, USA
| | - Carolina Río Bártulos
- Plant Ecophysiology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Manuel Serif
- Plant Ecophysiology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Marc Halder
- Plant Ecophysiology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Jan Henkel
- Plant Ecophysiology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany.,Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001, Bern, Switzerland
| | - Angela Falciatore
- Sorbonne Université, Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005, Paris, France
| | - Johann Lavaud
- UMI 3376 Takuvik, CNRS/ULaval, Département de Biologie, Pavillon Alexandre-Vachon, Université Laval, Québec (Québec), G1V 0A6, Canada
| | - Maxim Y Gorbunov
- Environmental Biophysics and Molecular Ecology Program, Department of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08901, USA
| | - Peter G Kroth
- Plant Ecophysiology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Paul G Falkowski
- Environmental Biophysics and Molecular Ecology Program, Department of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, 08901, USA
| | - Bernard Lepetit
- Plant Ecophysiology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany. .,Zukunftskolleg, University of Konstanz, 78457, Konstanz, Germany.
| |
Collapse
|
12
|
Kroth PG, Bones AM, Daboussi F, Ferrante MI, Jaubert M, Kolot M, Nymark M, Río Bártulos C, Ritter A, Russo MT, Serif M, Winge P, Falciatore A. Genome editing in diatoms: achievements and goals. Plant Cell Rep 2018; 37:1401-1408. [PMID: 30167805 DOI: 10.1007/s00299-018-2334-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 08/07/2018] [Indexed: 05/20/2023]
Abstract
Diatoms are major components of phytoplankton and play a key role in the ecology of aquatic ecosystems. These algae are of great scientific importance for a wide variety of research areas, ranging from marine ecology and oceanography to biotechnology. During the last 20 years, the availability of genomic information on selected diatom species and a substantial progress in genetic manipulation, strongly contributed to establishing diatoms as molecular model organisms for marine biology research. Recently, tailored TALEN endonucleases and the CRISPR/Cas9 system were utilized in diatoms, allowing targeted genetic modifications and the generation of knockout strains. These approaches are extremely valuable for diatom research because breeding, forward genetic screens by random insertion, and chemical mutagenesis are not applicable to the available model species Phaeodactylum tricornutum and Thalassiosira pseudonana, which do not cross sexually in the lab. Here, we provide an overview of the genetic toolbox that is currently available for performing stable genetic modifications in diatoms. We also discuss novel challenges that need to be addressed to fully exploit the potential of these technologies for the characterization of diatom biology and for metabolic engineering.
Collapse
Affiliation(s)
- Peter G Kroth
- Fachbereich Biologie, Universität Konstanz, 78457, Konstanz, Germany.
| | - Atle M Bones
- Cell, Molecular Biology and Genomics Group, Department of Biology, Norwegian University of Science and Technology, 7491, Trondheim, Norway
| | - Fayza Daboussi
- LISBP, Université de Toulouse, CNRS, INSA, 135 Avenue de Rangueil, 31077, Toulouse, France
| | - Maria I Ferrante
- Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale 1, Naples, 80121, Italy
| | - Marianne Jaubert
- Laboratoire de Biologie Computationnelle et Quantitative, Institut de Biologie Paris-Seine, Sorbonne Université, CNRS, 75005, Paris, France
| | - Misha Kolot
- Institute of Plant Sciences and Genetics in Agriculture, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100, Rehovot, Israel
- Department of Biochemistry and Molecular Biology, Tel-Aviv University, Tel-Aviv, 69978, Israel
| | - Marianne Nymark
- Cell, Molecular Biology and Genomics Group, Department of Biology, Norwegian University of Science and Technology, 7491, Trondheim, Norway
| | | | - Andrés Ritter
- Laboratoire de Biologie Computationnelle et Quantitative, Institut de Biologie Paris-Seine, Sorbonne Université, CNRS, 75005, Paris, France
| | - Monia T Russo
- Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale 1, Naples, 80121, Italy
| | - Manuel Serif
- LISBP, Université de Toulouse, CNRS, INSA, 135 Avenue de Rangueil, 31077, Toulouse, France
| | - Per Winge
- Cell, Molecular Biology and Genomics Group, Department of Biology, Norwegian University of Science and Technology, 7491, Trondheim, Norway
| | - Angela Falciatore
- Laboratoire de Biologie Computationnelle et Quantitative, Institut de Biologie Paris-Seine, Sorbonne Université, CNRS, 75005, Paris, France.
| |
Collapse
|
13
|
Taddei L, Chukhutsina VU, Lepetit B, Stella GR, Bassi R, van Amerongen H, Bouly JP, Jaubert M, Finazzi G, Falciatore A. Dynamic Changes between Two LHCX-Related Energy Quenching Sites Control Diatom Photoacclimation. Plant Physiol 2018; 177:953-965. [PMID: 29773581 PMCID: PMC6053010 DOI: 10.1104/pp.18.00448] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 05/04/2018] [Indexed: 05/20/2023]
Abstract
Marine diatoms are prominent phytoplankton organisms that perform photosynthesis in extremely variable environments. Diatoms possess a strong ability to dissipate excess absorbed energy as heat via nonphotochemical quenching (NPQ). This process relies on changes in carotenoid pigment composition (xanthophyll cycle) and on specific members of the light-harvesting complex family specialized in photoprotection (LHCXs), which potentially act as NPQ effectors. However, the link between light stress, NPQ, and the existence of different LHCX isoforms is not understood in these organisms. Using picosecond fluorescence analysis, we observed two types of NPQ in the pennate diatom Phaeodactylum tricornutum that were dependent on light conditions. Short exposure of low-light-acclimated cells to high light triggers the onset of energy quenching close to the core of photosystem II, while prolonged light stress activates NPQ in the antenna. Biochemical analysis indicated a link between the changes in the NPQ site/mechanism and the induction of different LHCX isoforms, which accumulate either in the antenna complexes or in the core complex. By comparing the responses of wild-type cells and transgenic lines with a reduced expression of the major LHCX isoform, LHCX1, we conclude that core complex-associated NPQ is more effective in photoprotection than is the antenna complex. Overall, our data clarify the complex molecular scenario of light responses in diatoms and provide a rationale for the existence of a degenerate family of LHCX proteins in these algae.
Collapse
Affiliation(s)
- Lucilla Taddei
- Sorbonne Université, Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005 Paris, France
| | - Volha U Chukhutsina
- Laboratory of Biophysics and MicroSpectroscopy Research Facility, Wageningen University, 6700ET Wageningen, The Netherlands
- Biophysics of Photosynthesis, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam and LaserLaB Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Bernard Lepetit
- Zukunftskolleg, Department of Plant Ecophysiology, University of Konstanz, 78457 Konstanz, Germany
| | - Giulio Rocco Stella
- Sorbonne Université, Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005 Paris, France
- Department of Biotechnology, University of Verona, I-37134 Verona, Italy
| | - Roberto Bassi
- Department of Biotechnology, University of Verona, I-37134 Verona, Italy
| | - Herbert van Amerongen
- Laboratory of Biophysics and MicroSpectroscopy Research Facility, Wageningen University, 6700ET Wageningen, The Netherlands
| | - Jean-Pierre Bouly
- Sorbonne Université, Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005 Paris, France
| | - Marianne Jaubert
- Sorbonne Université, Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005 Paris, France
| | - Giovanni Finazzi
- Université Grenoble Alpes, Laboratoire de Physiologie Cellulaire et Végétale, Unité Mixte de Recherche 5168, Centre National de la Recherche Scientifique, Institut National Recherche Agronomique, Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biosciences et Biotechnologies de Grenoble, CEA Grenoble, F-38054 Grenoble cedex 9, France
| | - Angela Falciatore
- Sorbonne Université, Centre National de la Recherche Scientifique, Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, F-75005 Paris, France
| |
Collapse
|
14
|
Villanova V, Fortunato AE, Singh D, Bo DD, Conte M, Obata T, Jouhet J, Fernie AR, Marechal E, Falciatore A, Pagliardini J, Le Monnier A, Poolman M, Curien G, Petroutsos D, Finazzi G. Investigating mixotrophic metabolism in the model diatom Phaeodactylum tricornutum. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0404. [PMID: 28717014 DOI: 10.1098/rstb.2016.0404] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2017] [Indexed: 12/14/2022] Open
Abstract
Diatoms are prominent marine microalgae, interesting not only from an ecological point of view, but also for their possible use in biotechnology applications. They can be cultivated in phototrophic conditions, using sunlight as the sole energy source. Some diatoms, however, can also grow in a mixotrophic mode, wherein both light and external reduced carbon contribute to biomass accumulation. In this study, we investigated the consequences of mixotrophy on the growth and metabolism of the pennate diatom Phaeodactylum tricornutum, using glycerol as the source of reduced carbon. Transcriptomics, metabolomics, metabolic modelling and physiological data combine to indicate that glycerol affects the central-carbon, carbon-storage and lipid metabolism of the diatom. In particular, provision of glycerol mimics typical responses of nitrogen limitation on lipid metabolism at the level of triacylglycerol accumulation and fatty acid composition. The presence of glycerol, despite provoking features reminiscent of nutrient limitation, neither diminishes photosynthetic activity nor cell growth, revealing essential aspects of the metabolic flexibility of these microalgae and suggesting possible biotechnological applications of mixotrophy.This article is part of the themed issue 'The peculiar carbon metabolism in diatoms'.
Collapse
Affiliation(s)
- Valeria Villanova
- Fermentalg SA, 33500 Libourne, France.,Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes (UGA), Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut National Recherche Agronomique (INRA), Institut de Biosciences et Biotechnologies de Grenoble (BIG), CEA Grenoble, F-38000 Grenoble, France
| | - Antonio Emidio Fortunato
- Laboratoire de Biologie Computationnelle et Quantitative, Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, 15 rue de l'Ecole de Médecine, Paris 75006, France
| | - Dipali Singh
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
| | - Davide Dal Bo
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes (UGA), Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut National Recherche Agronomique (INRA), Institut de Biosciences et Biotechnologies de Grenoble (BIG), CEA Grenoble, F-38000 Grenoble, France
| | - Melissa Conte
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes (UGA), Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut National Recherche Agronomique (INRA), Institut de Biosciences et Biotechnologies de Grenoble (BIG), CEA Grenoble, F-38000 Grenoble, France
| | - Toshihiro Obata
- Max-Planck Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Golm-Potsdam, Germany
| | - Juliette Jouhet
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes (UGA), Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut National Recherche Agronomique (INRA), Institut de Biosciences et Biotechnologies de Grenoble (BIG), CEA Grenoble, F-38000 Grenoble, France
| | - Alisdair R Fernie
- Max-Planck Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476 Golm-Potsdam, Germany
| | - Eric Marechal
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes (UGA), Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut National Recherche Agronomique (INRA), Institut de Biosciences et Biotechnologies de Grenoble (BIG), CEA Grenoble, F-38000 Grenoble, France
| | - Angela Falciatore
- Laboratoire de Biologie Computationnelle et Quantitative, Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, 15 rue de l'Ecole de Médecine, Paris 75006, France
| | | | | | - Mark Poolman
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford OX3 0BP, UK
| | - Gilles Curien
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes (UGA), Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut National Recherche Agronomique (INRA), Institut de Biosciences et Biotechnologies de Grenoble (BIG), CEA Grenoble, F-38000 Grenoble, France
| | - Dimitris Petroutsos
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes (UGA), Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut National Recherche Agronomique (INRA), Institut de Biosciences et Biotechnologies de Grenoble (BIG), CEA Grenoble, F-38000 Grenoble, France
| | - Giovanni Finazzi
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes (UGA), Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut National Recherche Agronomique (INRA), Institut de Biosciences et Biotechnologies de Grenoble (BIG), CEA Grenoble, F-38000 Grenoble, France
| |
Collapse
|
15
|
Kirkham AR, Richthammer P, Schmidt K, Wustmann M, Maeda Y, Hedrich R, Brunner E, Tanaka T, van Pée KH, Falciatore A, Mock T. A role for the cell-wall protein silacidin in cell size of the diatom Thalassiosira pseudonana. ISME J 2017; 11:2452-2464. [PMID: 28731468 PMCID: PMC5649158 DOI: 10.1038/ismej.2017.100] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 04/28/2017] [Accepted: 05/19/2017] [Indexed: 01/06/2023]
Abstract
Diatoms contribute 20% of global primary production and form the basis of many marine food webs. Although their species diversity correlates with broad diversity in cell size, there is also an intraspecific cell-size plasticity owing to sexual reproduction and varying environmental conditions. However, despite the ecological significance of the diatom cell size for food-web structure and global biogeochemical cycles, our knowledge about genes underpinning the size of diatom cells remains elusive. Here, a combination of reverse genetics, experimental evolution and comparative RNA-sequencing analyses enabled us to identify a previously unknown genetic control of cell size in the diatom Thalassiosira pseudonana. In particular, the targeted deregulation of the expression of the cell-wall protein silacidin caused a significant increase in valve diameter. Remarkably, the natural downregulation of the silacidin gene transcript due to experimental evolution under low temperature also correlated with cell-size increase. Our data give first evidence for a genetically controlled regulation of cell size in T. pseudonana and possibly other centric diatoms as they also encode the silacidin gene in their genomes.
Collapse
Affiliation(s)
- Amy R Kirkham
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | | | - Katrin Schmidt
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | | | - Yoshiaki Maeda
- Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - René Hedrich
- Allgemeine Biochemie, TU Dresden, Dresden, Germany
| | - Eike Brunner
- Allgemeine Biochemie, TU Dresden, Dresden, Germany
| | - Tsuyoshi Tanaka
- Tokyo University of Agriculture and Technology, Tokyo, Japan
| | | | - Angela Falciatore
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, Paris, France
| | - Thomas Mock
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| |
Collapse
|
16
|
Jaubert M, Bouly JP, Ribera d'Alcalà M, Falciatore A. Light sensing and responses in marine microalgae. Curr Opin Plant Biol 2017; 37:70-77. [PMID: 28456112 DOI: 10.1016/j.pbi.2017.03.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 03/13/2017] [Indexed: 06/07/2023]
Abstract
Marine eukaryotic phytoplankton are major contributors to global primary production. To adapt and thrive in the oceans, phytoplankton relies on a variety of light-regulated responses and light-acclimation capacities probably driven by sophisticated photoregulatory mechanisms. A plethora of photoreceptor-like sequences from marine microalgae have been identified in omics approaches. Initial studies have revealed that some algal photoreceptors are similar to those known in plants. In addition, new variants with different spectral tuning and algal-specific light sensors have also been found, changing current views and perspectives on how photoreceptor structure and function have diversified in phototrophs experiencing different environmental conditions.
Collapse
Affiliation(s)
- Marianne Jaubert
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 4, Place de Jussieu, 75005 Paris, France
| | - Jean-Pierre Bouly
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 4, Place de Jussieu, 75005 Paris, France
| | - Maurizio Ribera d'Alcalà
- Stazione Zoologica Anton Dohrn, Laboratory of Ecology and Evolution of Plankton, Villa Comunale, 80121 Naples, Italy.
| | - Angela Falciatore
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 4, Place de Jussieu, 75005 Paris, France.
| |
Collapse
|
17
|
Moejes FW, Matuszynska A, Adhikari K, Bassi R, Cariti F, Cogne G, Dikaios I, Falciatore A, Finazzi G, Flori S, Goldschmidt-Clermont M, Magni S, Maguire J, Le Monnier A, Müller K, Poolman M, Singh D, Spelberg S, Stella GR, Succurro A, Taddei L, Urbain B, Villanova V, Zabke C, Ebenhöh O. A systems-wide understanding of photosynthetic acclimation in algae and higher plants. J Exp Bot 2017; 68:2667-2681. [PMID: 28830099 DOI: 10.1093/jxb/erx137] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 03/28/2017] [Indexed: 05/27/2023]
Abstract
The ability of phototrophs to colonise different environments relies on robust protection against oxidative stress, a critical requirement for the successful evolutionary transition from water to land. Photosynthetic organisms have developed numerous strategies to adapt their photosynthetic apparatus to changing light conditions in order to optimise their photosynthetic yield, which is crucial for life on Earth to exist. Photosynthetic acclimation is an excellent example of the complexity of biological systems, where highly diverse processes, ranging from electron excitation over protein protonation to enzymatic processes coupling ion gradients with biosynthetic activity, interact on drastically different timescales from picoseconds to hours. Efficient functioning of the photosynthetic apparatus and its protection is paramount for efficient downstream processes, including metabolism and growth. Modern experimental techniques can be successfully integrated with theoretical and mathematical models to promote our understanding of underlying mechanisms and principles. This review aims to provide a retrospective analysis of multidisciplinary photosynthetic acclimation research carried out by members of the Marie Curie Initial Training Project, AccliPhot, placing the results in a wider context. The review also highlights the applicability of photosynthetic organisms for industry, particularly with regards to the cultivation of microalgae. It intends to demonstrate how theoretical concepts can successfully complement experimental studies broadening our knowledge of common principles in acclimation processes in photosynthetic organisms, as well as in the field of applied microalgal biotechnology.
Collapse
Affiliation(s)
- Fiona Wanjiku Moejes
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Quantitative and Theoretical Biology, Heinrich Heine University Düsseldorf, Germany
- Bantry Marine Research Station, Gearhies, Bantry, Co. Cork, Ireland P75 AX07
| | - Anna Matuszynska
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Quantitative and Theoretical Biology, Heinrich Heine University Düsseldorf, Germany
| | - Kailash Adhikari
- Department of Biological and Medical Sciences, Oxford Brookes University, United Kingdom
| | - Roberto Bassi
- University of Verona, Department of Biotechnology, Italy
| | - Federica Cariti
- Department of Botany and Plant Biology, University of Geneva, Switzerland
| | | | | | - Angela Falciatore
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 15 rue de l'Ecole de Médecine, 75006 Paris, France
| | - Giovanni Finazzi
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut National Recherche Agronomique (INRA), Institut de Biosciences et Biotechnologie de Grenoble (BIG), Université Grenoble Alpes (UGA), Grenoble 38100, France
| | - Serena Flori
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut National Recherche Agronomique (INRA), Institut de Biosciences et Biotechnologie de Grenoble (BIG), Université Grenoble Alpes (UGA), Grenoble 38100, France
| | | | - Stefano Magni
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Quantitative and Theoretical Biology, Heinrich Heine University Düsseldorf, Germany
| | - Julie Maguire
- Bantry Marine Research Station, Gearhies, Bantry, Co. Cork, Ireland P75 AX07
| | | | - Kathrin Müller
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Quantitative and Theoretical Biology, Heinrich Heine University Düsseldorf, Germany
| | - Mark Poolman
- Bantry Marine Research Station, Gearhies, Bantry, Co. Cork, Ireland P75 AX07
| | - Dipali Singh
- Bantry Marine Research Station, Gearhies, Bantry, Co. Cork, Ireland P75 AX07
| | - Stephanie Spelberg
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Quantitative and Theoretical Biology, Heinrich Heine University Düsseldorf, Germany
| | - Giulio Rocco Stella
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 15 rue de l'Ecole de Médecine, 75006 Paris, France
| | - Antonella Succurro
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Quantitative and Theoretical Biology, Heinrich Heine University Düsseldorf, Germany
| | - Lucilla Taddei
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 15 rue de l'Ecole de Médecine, 75006 Paris, France
| | - Brieuc Urbain
- LUNAM, University of Nantes, GEPEA, UMR-CNRS 6144, France
| | | | | | - Oliver Ebenhöh
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Quantitative and Theoretical Biology, Heinrich Heine University Düsseldorf, Germany
| |
Collapse
|
18
|
Lepetit B, Gélin G, Lepetit M, Sturm S, Vugrinec S, Rogato A, Kroth PG, Falciatore A, Lavaud J. The diatom Phaeodactylum tricornutum adjusts nonphotochemical fluorescence quenching capacity in response to dynamic light via fine-tuned Lhcx and xanthophyll cycle pigment synthesis. New Phytol 2017; 214:205-218. [PMID: 27870063 DOI: 10.1111/nph.14337] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 10/17/2016] [Indexed: 05/24/2023]
Abstract
Diatoms contain a highly flexible capacity to dissipate excessively absorbed light by nonphotochemical fluorescence quenching (NPQ) based on the light-induced conversion of diadinoxanthin (Dd) into diatoxanthin (Dt) and the presence of Lhcx proteins. Their NPQ fine regulation on the molecular level upon a shift to dynamic light conditions is unknown. We investigated the regulation of Dd + Dt amount, Lhcx gene and protein synthesis and NPQ capacity in the diatom Phaeodactylum tricornutum after a change from continuous low light to 3 d of sine (SL) or fluctuating (FL) light conditions. Four P. tricornutum strains with different NPQ capacities due to different expression of Lhcx1 were included. All strains responded to dynamic light comparably, independently of initial NPQ capacity. During SL, NPQ capacity was strongly enhanced due to a gradual increase of Lhcx2 and Dd + Dt amount. During FL, cells enhanced their NPQ capacity on the first day due to increased Dd + Dt, Lhcx2 and Lhcx3; already by the second day light acclimation was accomplished. While quenching efficiency of Dt was strongly lowered during SL conditions, it remained high throughout the whole FL exposure. Our results highlight a more balanced and cost-effective photoacclimation strategy of P. tricornutum under FL than under SL conditions.
Collapse
Affiliation(s)
- Bernard Lepetit
- UMR7266 'LIENSs', CNRS Université de La Rochelle, Institut du Littoral et de l'Environnement, 2 rue Olympe de Gouges, La Rochelle, 17000, France
- Zukunftskolleg, Pflanzliche Ökophysiologie, Universität Konstanz, Konstanz, 78457, Germany
| | - Gautier Gélin
- UMR7266 'LIENSs', CNRS Université de La Rochelle, Institut du Littoral et de l'Environnement, 2 rue Olympe de Gouges, La Rochelle, 17000, France
| | - Mariana Lepetit
- UMR7266 'LIENSs', CNRS Université de La Rochelle, Institut du Littoral et de l'Environnement, 2 rue Olympe de Gouges, La Rochelle, 17000, France
| | - Sabine Sturm
- Zukunftskolleg, Pflanzliche Ökophysiologie, Universität Konstanz, Konstanz, 78457, Germany
| | - Sascha Vugrinec
- Zukunftskolleg, Pflanzliche Ökophysiologie, Universität Konstanz, Konstanz, 78457, Germany
| | - Alessandra Rogato
- Institute of Biosciences and BioResources, CNR, Via P. Castellino 111, Naples, 80131, Italy
- Stazione Zoologica Anton Dohrn Villa Comunale, Naples, 80121, Italy
| | - Peter G Kroth
- Zukunftskolleg, Pflanzliche Ökophysiologie, Universität Konstanz, Konstanz, 78457, Germany
| | - Angela Falciatore
- Laboratoire de Biologie Computationnelle et Quantitative, Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, 15 rue de l'Ecole de Médecine, Paris, 75006, France
| | - Johann Lavaud
- UMR7266 'LIENSs', CNRS Université de La Rochelle, Institut du Littoral et de l'Environnement, 2 rue Olympe de Gouges, La Rochelle, 17000, France
- Département de Biologie, UMI 3376 TAKUVIK, CNRS/Université Laval, Pavillon Alexandre-Vachon, 1045 avenue de la Médecine, Québec, QC, G1V 0A6, Canada
| |
Collapse
|
19
|
Gherardi M, Amato A, Bouly JP, Cheminant S, Ferrante MI, d'Alcalá MR, Iudicone D, Falciatore A, Cosentino Lagomarsino M. Regulation of chain length in two diatoms as a growth-fragmentation process. Phys Rev E 2016; 94:022418. [PMID: 27627344 DOI: 10.1103/physreve.94.022418] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Indexed: 11/07/2022]
Abstract
Chain formation in diatoms is relevant because of several aspects of their adaptation to the ecosystem. However, the tools to quantify the regulation of their assemblage and infer specific mechanisms in a laboratory setting are scarce. To address this problem, we define an approach based on a statistical physics model of chain growth and separation in combination with experimental evaluation of chain-length distributions. Applying this combined analysis to data from Chaetoceros decipiens and Phaeodactylum tricornutum, we find that cells of the first species control chain separation, likely through a cell-to-cell communication process, while the second species only modulates the separation rate. These results promote quantitative methods for characterizing chain formation in several chain-forming species and in diatoms in particular.
Collapse
Affiliation(s)
- Marco Gherardi
- Dipartimento di Fisica, University of Milano, Via Celoria 16, Milano, Italy.,INFN, Milano, Italy.,Sorbonne Universités, UPMC Université Paris 6, UMR 7238, Computational and Quantitative Biology, 15 rue de l'École de Médecine, Paris, France
| | - Alberto Amato
- Stazione Zoologica Anton Dohrn, Department of Integrative Marine Ecology, Villa Comunale, Naples, Italy
| | - Jean-Pierre Bouly
- Sorbonne Universités, UPMC Université Paris 6, UMR 7238, Computational and Quantitative Biology, 15 rue de l'École de Médecine, Paris, France
| | - Soizic Cheminant
- Sorbonne Universités, UPMC Université Paris 6, UMR 7238, Computational and Quantitative Biology, 15 rue de l'École de Médecine, Paris, France
| | - Maria Immacolata Ferrante
- Stazione Zoologica Anton Dohrn, Department of Integrative Marine Ecology, Villa Comunale, Naples, Italy
| | - Maurizio Ribera d'Alcalá
- Stazione Zoologica Anton Dohrn, Department of Integrative Marine Ecology, Villa Comunale, Naples, Italy
| | - Daniele Iudicone
- Stazione Zoologica Anton Dohrn, Department of Integrative Marine Ecology, Villa Comunale, Naples, Italy
| | - Angela Falciatore
- Sorbonne Universités, UPMC Université Paris 6, UMR 7238, Computational and Quantitative Biology, 15 rue de l'École de Médecine, Paris, France.,CNRS, UMR 7238, Paris, France
| | - Marco Cosentino Lagomarsino
- Sorbonne Universités, UPMC Université Paris 6, UMR 7238, Computational and Quantitative Biology, 15 rue de l'École de Médecine, Paris, France.,CNRS, UMR 7238, Paris, France
| |
Collapse
|
20
|
Taddei L, Stella GR, Rogato A, Bailleul B, Fortunato AE, Annunziata R, Sanges R, Thaler M, Lepetit B, Lavaud J, Jaubert M, Finazzi G, Bouly JP, Falciatore A. Multisignal control of expression of the LHCX protein family in the marine diatom Phaeodactylum tricornutum. J Exp Bot 2016; 67:3939-51. [PMID: 27225826 PMCID: PMC4915529 DOI: 10.1093/jxb/erw198] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Diatoms are phytoplanktonic organisms that grow successfully in the ocean where light conditions are highly variable. Studies of the molecular mechanisms of light acclimation in the marine diatom Phaeodactylum tricornutum show that carotenoid de-epoxidation enzymes and LHCX1, a member of the light-harvesting protein family, both contribute to dissipate excess light energy through non-photochemical quenching (NPQ). In this study, we investigate the role of the other members of the LHCX family in diatom stress responses. Our analysis of available genomic data shows that the presence of multiple LHCX genes is a conserved feature of diatom species living in different ecological niches. Moreover, an analysis of the levels of four P. tricornutum LHCX transcripts in relation to protein expression and photosynthetic activity indicates that LHCXs are differentially regulated under different light intensities and nutrient starvation, mostly modulating NPQ capacity. We conclude that multiple abiotic stress signals converge to regulate the LHCX content of cells, providing a way to fine-tune light harvesting and photoprotection. Moreover, our data indicate that the expansion of the LHCX gene family reflects functional diversification of its members which could benefit cells responding to highly variable ocean environments.
Collapse
Affiliation(s)
- Lucilla Taddei
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 15 rue de l'Ecole de Médecine, 75006 Paris, France
| | - Giulio Rocco Stella
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 15 rue de l'Ecole de Médecine, 75006 Paris, France Department of Biotechnology, University of Verona, Strada Le Grazie, I-37134 Verona, Italy
| | - Alessandra Rogato
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 15 rue de l'Ecole de Médecine, 75006 Paris, France Institute of Biosciences and BioResources, CNR, Via P. Castellino 111, 80131 Naples, Italy Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
| | - Benjamin Bailleul
- Institut de Biologie Physico-Chimique, UMR 7141 CNRS-UPMC, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Antonio Emidio Fortunato
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 15 rue de l'Ecole de Médecine, 75006 Paris, France
| | - Rossella Annunziata
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 15 rue de l'Ecole de Médecine, 75006 Paris, France
| | - Remo Sanges
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
| | - Michael Thaler
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 15 rue de l'Ecole de Médecine, 75006 Paris, France
| | - Bernard Lepetit
- Zukunftskolleg, Department of Plant Ecophysiology, University of Konstanz, D-78457 Konstanz, Germany
| | - Johann Lavaud
- UMI 3376 TAKUVIK, CNRS/Université Laval, Département de Biologie, Pavillon Alexandre-Vachon, 1045 avenue de la Médecine, Québec (Québec) G1V 0A6, Canada
| | - Marianne Jaubert
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 15 rue de l'Ecole de Médecine, 75006 Paris, France
| | - Giovanni Finazzi
- Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS), Institut National Recherche Agronomique (INRA), Université Grenoble Alpes, Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut de Biosciences et Biotechnologies de Grenoble, (BIG), CEA Grenoble, F-38054 Grenoble cedex 9, France
| | - Jean-Pierre Bouly
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 15 rue de l'Ecole de Médecine, 75006 Paris, France
| | - Angela Falciatore
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative, 15 rue de l'Ecole de Médecine, 75006 Paris, France
| |
Collapse
|
21
|
Fortunato AE, Jaubert M, Enomoto G, Bouly JP, Raniello R, Thaler M, Malviya S, Bernardes JS, Rappaport F, Gentili B, Huysman MJJ, Carbone A, Bowler C, d'Alcalà MR, Ikeuchi M, Falciatore A. Diatom Phytochromes Reveal the Existence of Far-Red-Light-Based Sensing in the Ocean. Plant Cell 2016; 28:616-28. [PMID: 26941092 PMCID: PMC4826011 DOI: 10.1105/tpc.15.00928] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 02/16/2016] [Accepted: 02/29/2016] [Indexed: 05/22/2023]
Abstract
The absorption of visible light in aquatic environments has led to the common assumption that aquatic organisms sense and adapt to penetrative blue/green light wavelengths but show little or no response to the more attenuated red/far-red wavelengths. Here, we show that two marine diatom species, Phaeodactylum tricornutum and Thalassiosira pseudonana, possess a bona fide red/far-red light sensing phytochrome (DPH) that uses biliverdin as a chromophore and displays accentuated red-shifted absorbance peaks compared with other characterized plant and algal phytochromes. Exposure to both red and far-red light causes changes in gene expression in P. tricornutum, and the responses to far-red light disappear in DPH knockout cells, demonstrating that P. tricornutum DPH mediates far-red light signaling. The identification of DPH genes in diverse diatom species widely distributed along the water column further emphasizes the ecological significance of far-red light sensing, raising questions about the sources of far-red light. Our analyses indicate that, although far-red wavelengths from sunlight are only detectable at the ocean surface, chlorophyll fluorescence and Raman scattering can generate red/far-red photons in deeper layers. This study opens up novel perspectives on phytochrome-mediated far-red light signaling in the ocean and on the light sensing and adaptive capabilities of marine phototrophs.
Collapse
Affiliation(s)
- Antonio Emidio Fortunato
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative UMR 7238, 75006 Paris, France
| | - Marianne Jaubert
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative UMR 7238, 75006 Paris, France
| | - Gen Enomoto
- Department of Life Sciences (Biology), Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo 153-8902, Japan
| | - Jean-Pierre Bouly
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative UMR 7238, 75006 Paris, France
| | | | - Michael Thaler
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative UMR 7238, 75006 Paris, France
| | - Shruti Malviya
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure, CNRS UMR 8197, INSERM U1024, F-75005 Paris, France
| | - Juliana Silva Bernardes
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative UMR 7238, 75006 Paris, France
| | - Fabrice Rappaport
- Institut de Biologie Physico-Chimique, UMR 7141 CNRS-UPMC, 75005 Paris, France
| | - Bernard Gentili
- Sorbonne Universités, UPMC Univ-Paris 6, CNRS, UMR 7093, Laboratoire d'Océanologie de Villefranche, F-06230 Villefranche/mer, France
| | - Marie J J Huysman
- Protistology and Aquatic Ecology, Department of Biology, Ghent University, B-9000 Gent, Belgium Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium
| | - Alessandra Carbone
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative UMR 7238, 75006 Paris, France Institut Universitaire de France, 75005 Paris, France
| | - Chris Bowler
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure, CNRS UMR 8197, INSERM U1024, F-75005 Paris, France
| | | | - Masahiko Ikeuchi
- Department of Life Sciences (Biology), Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo 153-8902, Japan
| | - Angela Falciatore
- Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, CNRS, Laboratoire de Biologie Computationnelle et Quantitative UMR 7238, 75006 Paris, France
| |
Collapse
|
22
|
Russo MT, Annunziata R, Sanges R, Ferrante MI, Falciatore A. The upstream regulatory sequence of the light harvesting complex Lhcf2 gene of the marine diatom Phaeodactylum tricornutum enhances transcription in an orientation- and distance-independent fashion. Mar Genomics 2015; 24 Pt 1:69-79. [PMID: 26117181 DOI: 10.1016/j.margen.2015.06.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 05/31/2015] [Accepted: 06/17/2015] [Indexed: 10/23/2022]
Abstract
Diatoms are a key phytoplankton group in the contemporary ocean, showing extraordinary adaptation capacities to rapidly changing environments. The recent availability of whole genome sequences from representative species has revealed distinct features in their genomes, like novel combinations of genes encoding distinct metabolisms and a significant number of diatom-specific genes. However, the regulatory mechanisms driving diatom gene expression are still largely uncharacterized. Considering the wide variety of fields of study orbiting diatoms, ranging from ecology, evolutionary biology to biotechnology, it is thus essential to increase our understanding of fundamental gene regulatory processes such as transcriptional regulation. To this aim, we explored the functional properties of the 5'-flanking region of the Phaeodatylum tricornutum Lhcf2 gene, encoding a member of the Light Harvesting Complex superfamily and we showed that this region enhances transcription of a GUS reporter gene in an orientation- and distance-independent fashion. This represents the first example of a cis-regulatory sequence with enhancer-like features discovered in diatoms and it is instrumental for the generation of novel genetic tools and diatom exploitation in different areas of study.
Collapse
Affiliation(s)
| | - Rossella Annunziata
- Sorbonne Universités, UPMC Univ Paris 06, Institut de Biologie Paris-Seine, UMR 7238, F-75006 Paris, France; CNRS, UMR 7238, F-75006 Paris, France
| | - Remo Sanges
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
| | | | - Angela Falciatore
- Sorbonne Universités, UPMC Univ Paris 06, Institut de Biologie Paris-Seine, UMR 7238, F-75006 Paris, France; CNRS, UMR 7238, F-75006 Paris, France.
| |
Collapse
|
23
|
Fortunato AE, Annunziata R, Jaubert M, Bouly JP, Falciatore A. Dealing with light: the widespread and multitasking cryptochrome/photolyase family in photosynthetic organisms. J Plant Physiol 2015; 172:42-54. [PMID: 25087009 DOI: 10.1016/j.jplph.2014.06.011] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 06/17/2014] [Accepted: 06/19/2014] [Indexed: 05/19/2023]
Abstract
Light is essential for the life of photosynthetic organisms as it is a source of energy and information from the environment. Light excess or limitation can be a cause of stress however. Photosynthetic organisms exhibit sophisticated mechanisms to adjust their physiology and growth to the local environmental light conditions. The cryptochrome/photolyase family (CPF) is composed of flavoproteins with similar structures that display a variety of light-dependent functions. This family encompasses photolyases, blue-light activated enzymes that repair ultraviolet-light induced DNA damage, and cryptochromes, known for their photoreceptor functions in terrestrial plants. For this review, we searched extensively for CPFs in the available genome databases to trace the distribution and evolution of this protein family in photosynthetic organisms. By merging molecular data with current knowledge from the functional characterization of CPFs from terrestrial and aquatic organisms, we discuss their roles in (i) photoperception, (ii) biological rhythm regulation and (iii) light-induced stress responses. We also explore their possible implication in light-related physiological acclimation and their distribution in phototrophs living in different environments. The outcome of this structure-function analysis reconstructs the complex scenarios in which CPFs have evolved, as highlighted by the novel functions and biochemical properties of the most recently described family members in algae.
Collapse
Affiliation(s)
- Antonio Emidio Fortunato
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7238, Computational and Quantitative Biology, F-75006 Paris, France; CNRS, UMR 7238, Computational and Quantitative Biology, F-75006 Paris, France
| | - Rossella Annunziata
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7238, Computational and Quantitative Biology, F-75006 Paris, France; CNRS, UMR 7238, Computational and Quantitative Biology, F-75006 Paris, France
| | - Marianne Jaubert
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7238, Computational and Quantitative Biology, F-75006 Paris, France; CNRS, UMR 7238, Computational and Quantitative Biology, F-75006 Paris, France
| | - Jean-Pierre Bouly
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7238, Computational and Quantitative Biology, F-75006 Paris, France; CNRS, UMR 7238, Computational and Quantitative Biology, F-75006 Paris, France.
| | - Angela Falciatore
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7238, Computational and Quantitative Biology, F-75006 Paris, France; CNRS, UMR 7238, Computational and Quantitative Biology, F-75006 Paris, France.
| |
Collapse
|
24
|
Rogato A, Richard H, Sarazin A, Voss B, Cheminant Navarro S, Champeimont R, Navarro L, Carbone A, Hess WR, Falciatore A. The diversity of small non-coding RNAs in the diatom Phaeodactylum tricornutum. BMC Genomics 2014; 15:698. [PMID: 25142710 PMCID: PMC4247016 DOI: 10.1186/1471-2164-15-698] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 07/30/2014] [Indexed: 11/10/2022] Open
Abstract
Background Marine diatoms constitute a major component of eukaryotic phytoplankton and stand at the crossroads of several evolutionary lineages. These microalgae possess peculiar genomic features and novel combinations of genes acquired from bacterial, animal and plant ancestors. Furthermore, they display both DNA methylation and gene silencing activities. Yet, the biogenesis and regulatory function of small RNAs (sRNAs) remain ill defined in diatoms. Results Here we report the first comprehensive characterization of the sRNA landscape and its correlation with genomic and epigenomic information in Phaeodactylum tricornutum. The majority of sRNAs is 25 to 30 nt-long and maps to repetitive and silenced Transposable Elements marked by DNA methylation. A subset of this population also targets DNA methylated protein-coding genes, suggesting that gene body methylation might be sRNA-driven in diatoms. Remarkably, 25-30 nt sRNAs display a well-defined and unprecedented 180 nt-long periodic distribution at several highly methylated regions that awaits characterization. While canonical miRNAs are not detectable, other 21-25 nt sRNAs of unknown origin are highly expressed. Besides, non-coding RNAs with well-described function, namely tRNAs and U2 snRNA, constitute a major source of 21-25 nt sRNAs and likely play important roles under stressful environmental conditions. Conclusions P. tricornutum has evolved diversified sRNA pathways, likely implicated in the regulation of largely still uncharacterized genetic and epigenetic processes. These results uncover an unexpected complexity of diatom sRNA population and previously unappreciated features, providing new insights into the diversification of sRNA-based processes in eukaryotes. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-698) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
| | - Hugues Richard
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7238, Laboratory of Computational and Quantitative Biology, F-75006 Paris, France.
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Affiliation(s)
- Chris Bowler
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR8197 Inserm U1024, 75005 Paris, France
| | - Angela Falciatore
- Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR 7238, Laboratory of Computational and Quantitative Biology, F-75006 Paris, France
| |
Collapse
|
26
|
Raible F, Falciatore A. It's about time: rhythms as a new dimension of molecular marine research. Mar Genomics 2014; 14:1-2. [PMID: 24952925 DOI: 10.1016/j.margen.2014.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2013] [Revised: 03/10/2014] [Accepted: 03/25/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Florian Raible
- Max F. Perutz Laboratories and Research Platform "Marine Rhythms of Life", University of Vienna, Dr. Bohr-Gasse 9/4, A-1030 Vienna, Austria.
| | - Angela Falciatore
- Sorbonne Universités, UPMC Univ Paris 06, Laboratory of Computational and Quantitative Biology UMR 7238CNRS-UPMC, F-75006 Paris, France.
| |
Collapse
|
27
|
Oliveri P, Fortunato AE, Petrone L, Ishikawa-Fujiwara T, Kobayashi Y, Todo T, Antonova O, Arboleda E, Zantke J, Tessmar-Raible K, Falciatore A. The Cryptochrome/Photolyase Family in aquatic organisms. Mar Genomics 2014; 14:23-37. [DOI: 10.1016/j.margen.2014.02.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/05/2014] [Accepted: 02/10/2014] [Indexed: 01/12/2023]
|
28
|
Lepetit B, Sturm S, Rogato A, Gruber A, Sachse M, Falciatore A, Kroth PG, Lavaud J. High light acclimation in the secondary plastids containing diatom Phaeodactylum tricornutum is triggered by the redox state of the plastoquinone pool. Plant Physiol 2013; 161:853-65. [PMID: 23209128 PMCID: PMC3561024 DOI: 10.1104/pp.112.207811] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 11/30/2012] [Indexed: 05/20/2023]
Abstract
In diatoms, the process of energy-dependent chlorophyll fluorescence quenching (qE) has an important role in photoprotection. Three components are essential for qE: (1) the light-dependent generation of a transthylakoidal proton gradient; (2) the deepoxidation of the xanthophyll diadinoxanthin (Dd) into diatoxanthin (Dt); and (3) specific nucleus-encoded antenna proteins, called Light Harvesting Complex Protein X (LHCX). We used the model diatom Phaeodactylum tricornutum to investigate the concerted light acclimation response of the qE key components LHCX, proton gradient, and xanthophyll cycle pigments (Dd+Dt) and to identify the intracellular light-responsive trigger. At high-light exposure, the up-regulation of three of the LHCX genes and the de novo synthesis of Dd+Dt led to a pronounced rise of qE. By inhibiting either the conversion of Dd to Dt or the translation of LHCX genes, qE amplification was abolished and the diatom cells suffered from stronger photoinhibition. Artificial modification of the redox state of the plastoquinone (PQ) pool via 3-(3,4-dichlorophenyl)-1,1-dimethylurea and 5-dibromo-6-isopropyl-3-methyl-1,4-benzoquinone resulted in a disturbance of Dd+Dt synthesis in an opposite way. Moreover, we could increase the transcription of two of the four LHCX genes under low-light conditions by reducing the PQ pool using 5-dibromo-6-isopropyl-3-methyl-1,4-benzoquinone. Altogether, our results underline the central role of the redox state of the PQ pool in the light acclimation of diatoms. Additionally, they emphasize strong evidence for the existence of a plastid-to-nucleus retrograde signaling mechanism in an organism with plastids that derived from secondary endosymbiosis.
Collapse
Affiliation(s)
- Bernard Lepetit
- Littoral Environnement et Sociétés, Unité Mixte de Recherche 7266, Centre National de la Recherche Scientifique-University of La Rochelle, Institute for Coastal and Environmental Research, 17000 La Rochelle, France.
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Huysman MJJ, Fortunato AE, Matthijs M, Costa BS, Vanderhaeghen R, Van den Daele H, Sachse M, Inzé D, Bowler C, Kroth PG, Wilhelm C, Falciatore A, Vyverman W, De Veylder L. AUREOCHROME1a-mediated induction of the diatom-specific cyclin dsCYC2 controls the onset of cell division in diatoms (Phaeodactylum tricornutum). Plant Cell 2013; 25:215-28. [PMID: 23292736 PMCID: PMC3584536 DOI: 10.1105/tpc.112.106377] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Cell division in photosynthetic organisms is tightly regulated by light. Although the light dependency of the onset of the cell cycle has been well characterized in various phototrophs, little is known about the cellular signaling cascades connecting light perception to cell cycle activation and progression. Here, we demonstrate that diatom-specific cyclin 2 (dsCYC2) in Phaeodactylum tricornutum displays a transcriptional peak within 15 min after light exposure, long before the onset of cell division. The product of dsCYC2 binds to the cyclin-dependent kinase CDKA1 and can complement G1 cyclin-deficient yeast. Consistent with the role of dsCYC2 in controlling a G1-to-S light-dependent cell cycle checkpoint, dsCYC2 silencing decreases the rate of cell division in diatoms exposed to light-dark cycles but not to constant light. Transcriptional induction of dsCYC2 is triggered by blue light in a fluence rate-dependent manner. Consistent with this, dsCYC2 is a transcriptional target of the blue light sensor AUREOCHROME1a, which functions synergistically with the basic leucine zipper (bZIP) transcription factor bZIP10 to induce dsCYC2 transcription. The functional characterization of a cyclin whose transcription is controlled by light and whose activity connects light signaling to cell cycle progression contributes significantly to our understanding of the molecular mechanisms underlying light-dependent cell cycle onset in diatoms.
Collapse
Affiliation(s)
- Marie J J Huysman
- Protistology and Aquatic Ecology, Department of Biology, Ghent University, B-9000 Gent, Belgium
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Abstract
Light is an essential source of energy for life on Earth and is one of the most important signals that organisms use to obtain information from the surrounding environment, on land and in the oceans. Prominent marine microalgae, such as diatoms, display a suite of sophisticated responses (physiological, biochemical, and behavioural) to optimize their photosynthesis and growth under changing light conditions. However, the molecular mechanisms controlling diatom responses to light are still largely unknown. Recent progress in marine diatom genomics and genetics, combined with well-established (eco) physiological and biophysical approaches, now offers novel opportunities to address these issues. This review provides a description of the molecular components identified in diatom genomes that are involved in light perception and acclimation mechanisms. How the initial functional characterizations of specific light regulators provide the basis to investigate the conservation or diversification of light-mediated processes in diatoms is also discussed. Hypotheses on the role of the identified factors in determining the growth, distribution, and adaptation of diatoms in different marine environments are reported.
Collapse
Affiliation(s)
- Frauke Angelique Depauw
- Université Pierre et Marie Curie, Paris 06, Centre National de la Recherche Scientifique, UMR7238, Laboratoire de Génomique des Microorganismes, 75006 Paris, France
| | | | | | | |
Collapse
|
31
|
Bowler C, De Martino A, Falciatore A. Diatom cell division in an environmental context. Curr Opin Plant Biol 2010; 13:623-630. [PMID: 20970371 DOI: 10.1016/j.pbi.2010.09.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 08/26/2010] [Accepted: 09/23/2010] [Indexed: 05/30/2023]
Abstract
Studies of cell division in organisms derived from secondary endosymbiosis such as diatoms have revealed that the mechanisms are far from those found in more conventional model eukaryotes. An atypical acentriolar microtuble-organizing centre, centripetal cytokinesis combined with centrifugal cell wall neosynthesis, and the role of sex in relation to cell size restoration make diatoms an exciting system to re-investigate the evolution, differentiation and regulation of cell division. Such studies are further justified considering the ecological relevance of these microalgae in contemporary oceans and the need to understand the mechanisms controlling their growth and distribution in an environmental context. Recent work derived from genome-wide analyses on representative model diatoms reveals that the cell cycle is finely tuned to inputs derived from both endogenous and environmental signals.
Collapse
Affiliation(s)
- Chris Bowler
- Environmental and Evolutionary Genomics Section, Institut de Biologie de l'Ecole Normale Supérieure, Centre National de la Recherche Scientifique UMR8197 INSERM U1024, F-75005 Paris, France.
| | | | | |
Collapse
|
32
|
Heijde M, Zabulon G, Corellou F, Ishikawa T, Brazard J, Usman A, Sanchez F, Plaza P, Martin M, Falciatore A, Todo T, Bouget FY, Bowler C. Characterization of two members of the cryptochrome/photolyase family from Ostreococcus tauri provides insights into the origin and evolution of cryptochromes. Plant Cell Environ 2010; 33:1614-1626. [PMID: 20444223 DOI: 10.1111/j.1365-3040.2010.02168.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Cryptochromes (Crys) are blue light receptors believed to have evolved from the DNA photolyase protein family, implying that light control and light protection share a common ancient origin. In this paper, we report the identification of five genes of the Cry/photolyase family (CPF) in two green algae of the Ostreococcus genus. Phylogenetic analyses were used to confidently assign three of these sequences to cyclobutane pyrimidine dimer (CPD) photolyases, one of them to a DASH-type Cry, and a third CPF gene has high homology with the recently described diatom CPF1 that displays a bifunctional activity. Both purified OtCPF1 and OtCPF2 proteins show non-covalent binding to flavin adenine dinucleotide (FAD), and additionally to 5,10-methenyl-tetrahydrofolate (MTHF) for OtCPF2. Expression analyses revealed that all five CPF members of Ostreococcus tauri are regulated by light. Furthermore, we show that OtCPF1 and OtCPF2 display photolyase activity and that OtCPF1 is able to interact with the CLOCK:BMAL heterodimer, transcription factors regulating circadian clock function in other organisms. Finally, we provide evidence for the involvement of OtCPF1 in the maintenance of the Ostreococcus circadian clock. This work improves our understanding of the evolutionary transition between photolyases and Crys.
Collapse
Affiliation(s)
- Marc Heijde
- Ecole Normale Supérieure, Institut de Biologie de l'ENS, IBENS, CNRS UMR 8197, Paris, F-75005 France
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
Diatoms are a major but poorly understood phytoplankton group. The recent completion of two whole genome sequences has revealed that they contain unique combinations of genes, likely recruited during their history as secondary endosymbionts, as well as by horizontal gene transfer from bacteria. A major limitation for the study of diatom biology and gene function is the lack of tools to generate targeted gene knockout or knockdown mutants. In this work, we have assessed the possibility of triggering gene silencing in Phaeodactylum tricornutum using constructs containing either anti-sense or inverted repeat sequences of selected target genes. We report the successful silencing of a GUS reporter gene expressed in transgenic lines, as well as the knockdown of endogenous phytochrome (DPH1) and cryptochrome (CPF1) genes. To highlight the utility of the approach we also report the first phenotypic characterization of a diatom mutant (cpf1). Our data open the way for reverse genetics in diatoms and represent a major advance for understanding their biology and ecology. Initial molecular analyses reveal that targeted downregulation likely occurs through transcriptional and post-transcriptional gene silencing mechanisms. Interestingly, molecular players involved in RNA silencing in other eukaryotes are only poorly conserved in diatoms.
Collapse
Affiliation(s)
- Valentina De Riso
- Laboratory of Ecology and Evolution of Plankton, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
| | | | | | | | | | | |
Collapse
|
34
|
Siaut M, Heijde M, Mangogna M, Montsant A, Coesel S, Allen A, Manfredonia A, Falciatore A, Bowler C. Molecular toolbox for studying diatom biology in Phaeodactylum tricornutum. Gene 2007; 406:23-35. [PMID: 17658702 DOI: 10.1016/j.gene.2007.05.022] [Citation(s) in RCA: 246] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2007] [Revised: 04/20/2007] [Accepted: 05/18/2007] [Indexed: 11/16/2022]
Abstract
Research into diatom biology has now entered the post-genomics era, following the recent completion of the Thalassiosira pseudonana and Phaeodactylum tricornutum whole genome sequences and the establishment of Expressed Sequence Tag (EST) databases. The thorough exploitation of these resources will require the development of molecular tools to analyze and modulate the function of diatom genes in vivo. Towards this objective, we report here the identification of several reference genes that can be used as internal standards for gene expression studies by quantitative real-time PCR (qRT-PCR) in P. tricornutum cells grown over a diel cycle. In addition, we describe a series of diatom expression vectors based on Invitrogen Gateway technology for high-throughput protein tagging and overexpression studies in P. tricornutum. We demonstrate the utility of the diatom Destination vectors for determining the subcellular localization of a protein of interest and for immunodetection. The availability of these new resources significantly enriches the molecular toolbox for P. tricornutum and provides the diatom research community with well defined high-throughput methods for the analysis of diatom genes and proteins in vivo.
Collapse
Affiliation(s)
- Magali Siaut
- Laboratory of Cell Signalling, Stazione Zoologica Anton Dohrn, Villa Comunale, Naples, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Falciatore A, Merendino L, Barneche F, Ceol M, Meskauskiene R, Apel K, Rochaix JD. The FLP proteins act as regulators of chlorophyll synthesis in response to light and plastid signals in Chlamydomonas. Genes Dev 2005; 19:176-87. [PMID: 15630026 PMCID: PMC540235 DOI: 10.1101/gad.321305] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In photosynthetic organisms the accumulation of harmful photodynamic chlorophyll precursors is prevented because of the tight regulation of the tetrapyrrole pathway. FLU is one of the regulatory factors involved in this process in land plants. We have examined the function of a Flu-like gene (FLP) from Chlamydomonas that gives rise to two FLP transcripts through alternative splicing. These transcripts are translated into a short and a long protein that differ by only 12 amino acids but that interact differently with glutamyl-tRNA reductase, an enzyme involved in an early step of the chlorophyll biosynthetic pathway. Expression of FLPs is light-regulated at the level of RNA accumulation and splicing and is altered by mutations affecting the pathway. The relative levels of the long and short forms of FLP can be correlated with the accumulation of specific porphyrin intermediates, some of which have been implicated in a signaling chain from the chloroplast to the nucleus. Reciprocally, reduction of the FLP proteins by RNA interference leads to the accumulation of several porphyrin intermediates and to photobleaching when cells are transferred from the dark to the light. Thus the FLP proteins act as regulators of chlorophyll synthesis, and their expression is controlled by light and plastid signals.
Collapse
Affiliation(s)
- Angela Falciatore
- Department of Molecular Biology, University of Geneva, 1211 Geneva, Switzerland
| | | | | | | | | | | | | |
Collapse
|
36
|
Abstract
Photoreceptors allow living organisms to optimize perception of light in the natural environment and thus to gain information about their external world. In this review, we describe blue and red light photoreceptors in bacteria, plants, and animals in relation to their evolution. Analyses performed in different organisms have revealed wonderful examples of structural modifications of the light-sensing proteins themselves, as well as diversification of the signal transduction pathways they use in relation with their evolutionary history and function. In different organisms, the same photoreceptor may have a very conserved role (convergent evolution of function) or may modulate different responses (acquisition of new function). Multiple photoreceptors of the same family in the same organism indicate gene duplication events during evolution, with a consequent enhanced sensitivity to variations in ambient light. Conversely, two different photoreceptors may be involved in the control of the same physiological response. Genomic analysis in marine diatoms, combined with phylogenetic studies, has also revealed the presence of blue and red light photoreceptors in the marine environment. This discovery has intriguing implications for the understanding of light perception and its evolution in photosynthetic organisms. In addition, the characterization of these photoreceptors likely will add to our understanding of photoreceptor diversity as an adaptation to different habitats.
Collapse
Affiliation(s)
- Angela Falciatore
- Cell Signalling Laboratory, Stazione Zoologica Anton Dohrn, Villa Comunale, I-80121 Naples, Italy
| | | |
Collapse
|
37
|
Merendino L, Falciatore A, Rochaix JD. Expression and RNA binding properties of the chloroplast ribosomal protein S1 from Chlamydomonas reinhardtii. Plant Mol Biol 2003; 53:371-82. [PMID: 14750525 DOI: 10.1023/b:plan.0000006941.56233.42] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The gene encoding the chloroplast ribosomal protein S1 from Chlamydomonas reinhardtii, CreS1, was cloned and the RNA binding properties and the expression patterns were studied. Gel-shift analysis revealed that CreS1 binds AU-rich 5'-untranslated regions (5'-UTR) of chloroplast mRNAs with higher affinity than the corresponding sequence of a GC-rich nuclear transcript. The binding affinity of CreS1 for a mutant form of the psbD 5'-UTR with a deletion of a U-rich stretch that is required for translation decreases 4-fold as compared to the wild-type 5'-UTR. Our results suggest that CreS1 protein interacts with U-rich sequences. Most of CreS1 is bound to high-molecular-weight complexes which co-migrate with the 30S small ribosomal subunit, and only a small fraction of CreS1 exists in its free form. CreS1 is localized mainly to the chloroplast stroma albeit a significant fraction is associated with chloroplast membranes. The results suggest that most of CreS1 is associated with the 30S ribosomal subunit throughout the translation process. Upon a shift of cells from the dark to the light, the mRNA levels of CreS1 and Psrp-7, both components of the 30S ribosomal subunit, increase transiently and return to the dark levels after 8 h. However, during this dark-to-light transition the levels of CreS1 and of other components of the 30S subunit remain the same suggesting that either protein synthesis or degradation is regulated. The possible implications of these findings are discussed.
Collapse
Affiliation(s)
- Livia Merendino
- Department of Molecular Biology, University of Geneva, 30, Quai Ernest Ansermet, 1211 Geneva 4, Switzerland
| | | | | |
Collapse
|
38
|
Scala S, Carels N, Falciatore A, Chiusano ML, Bowler C. Genome properties of the diatom Phaeodactylum tricornutum. Plant Physiol 2002; 129:993-1002. [PMID: 12114555 PMCID: PMC166495 DOI: 10.1104/pp.010713] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2001] [Revised: 01/28/2002] [Accepted: 03/28/2002] [Indexed: 05/20/2023]
Abstract
Diatoms are a ubiquitous class of microalgae of extreme importance for global primary productivity and for the biogeochemical cycling of minerals such as silica. However, very little is known about diatom cell biology or about their genome structure. For diatom researchers to take advantage of genomics and post-genomics technologies, it is necessary to establish a model diatom species. Phaeodactylum tricornutum is an obvious candidate because of its ease of culture and because it can be genetically transformed. Therefore, we have examined its genome composition by the generation of approximately 1,000 expressed sequence tags. Although more than 60% of the sequences could not be unequivocally identified by similarity to sequences in the databases, approximately 20% had high similarity with a range of genes defined functionally at the protein level. It is interesting that many of these sequences are more similar to animal rather than plant counterparts. Base composition at each codon position and GC content of the genome were compared with Arabidopsis, maize (Zea mays), and Chlamydomonas reinhardtii. It was found that distribution of GC within the coding sequences is as homogeneous in P. tricornutum as in Arabidopsis, but with a slightly higher GC content. Furthermore, we present evidence that the P. tricornutum genome is likely to be small (less than 20 Mb). Therefore, this combined information supports the development of this species as a model system for molecular-based studies of diatom biology. The nucleotide sequence data reported has been deposited in GenBank Nucleotide Sequence Database (dbEST section) under accession nos. BI306757 through BI307753.
Collapse
Affiliation(s)
- Simona Scala
- Laboratory of Molecular Plant Biology, Stazione Zoologica Anton Dohrn, Villa Comunale, I-80121 Naples, Italy
| | | | | | | | | |
Collapse
|
39
|
Abstract
Diatoms are unicellular photosynthetic eukaryotes that contribute close to one quarter of global primary productivity. In spite of their ecological success in the world's oceans, very little information is available at the molecular level about their biology. Their most well-known characteristic is the ability to generate a highly ornamented silica cell wall, which made them very popular study organisms for microscopists in the last century. Recent advances, such as the development of a range of molecular tools, are now allowing the dissection of diatom biology, e.g., for understanding the molecular and cellular basis of bioinorganic pattern formation of their cell walls and for elucidating key aspects of diatom ecophysiology. Making diatoms accessible to genomics technologies will potentiate greatly these efforts and may lead to the use of diatoms to construct submicrometer-scale silica structures for the nanotechnology industry.
Collapse
Affiliation(s)
- Angela Falciatore
- Laboratory of Molecular Plant Biology, Stazione Zoologica A. Dohrn, Villa Comunale, I-80121 Naples, Italy
| | | |
Collapse
|
40
|
Abstract
Diatoms are a key component of marine ecosystems and are extremely important for the biogeochemical cycling of silica and as contributors to global fixed carbon. However, the answers to fundamental questions such as what diatoms can sense in their environment, how they respond to external signals, and what factors control their life strategies are largely unknown. We generated transgenic diatom cells containing the calcium-sensitive photoprotein aequorin to determine whether changes in calcium homeostasis are used to respond to relevant environmental stimuli. Our results reveal sensing systems for detecting and responding to fluid motion (shear stress), osmotic stress, and iron, a key nutrient that controls diatom abundance in the ocean.
Collapse
Affiliation(s)
- A Falciatore
- Laboratories of Molecular Plant Biology and Biological Oceanography, Stazione Zoologica Anton Dohrn, Villa Comunale, I-80121 Naples, Italy
| | | | | | | |
Collapse
|
41
|
Leblanc C, Falciatore A, Watanabe M, Bowler C. Semi-quantitative RT-PCR analysis of photoregulated gene expression in marine diatoms. Plant Mol Biol 1999; 40:1031-1044. [PMID: 10527427 DOI: 10.1023/a:1006256300969] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The low cell densities of diatoms and other phytoplankton in culture has precluded the use of classical RNA analysis techniques for routine studies of gene expression in large numbers of samples. This has seriously hampered studies of the basic biology of such organisms. To circumvent this problem, we have developed a high-throughput semi-quantitative RT-PCR-based protocol and used it to monitor expression of a gene encoding a fucoxanthin, chlorophyll a/c-binding protein (FCP) in the centric planktonic diatom Thalassiosira weissflogii. Analysis of FCP gene expression in dark-adapted diatom cultures revealed that mRNA levels increase 5- to 6-fold in response to white light irradiation and peak around 6 to 8 h. To determine the photoreceptors involved in this response action spectra of FCP gene expression were determined using the Okazaki large spectrograph. Responses consistent with the presence of cryptochrome-, rhodopsin- and phytochrome-type receptors could be detected. The apparent presence of phytochrome-mediated responses is of particular interest given the low fluences of red and far-red light wavelengths in the marine environment.
Collapse
Affiliation(s)
- C Leblanc
- Laboratory of Molecular Plant Biology, Stazione Zoologica A. Dohrn, Naples, Italy
| | | | | | | |
Collapse
|
42
|
Falciatore A, Casotti R, Leblanc C, Abrescia C, Bowler C. Transformation of Nonselectable Reporter Genes in Marine Diatoms. Mar Biotechnol (NY) 1999; 1:239-251. [PMID: 10383998 DOI: 10.1007/pl00011773] [Citation(s) in RCA: 176] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
: We report the genetic transformation of two marine diatoms by microparticle bombardment. The pennate diatom Phaeodactylum tricornutum was transformed with the bacterial gene Sh ble from Streptoalloteichus hindustanus, which confers resistance to the antibiotics phleomycin and zeocin. Transformants contained between 1 and 10 copies of the exogenous DNA integrated into the genome by illegitimate recombination at apparently random locations. Transformation efficiencies were around 10(-6), and individual cell lines could be maintained at -80 degrees C following cryopreservation. Also, P. tricornutum could be transformed simultaneously with two different plasmids, one containing the Sh ble gene and another containing the firefly luciferase gene (LUC) under control of a promoter derived from a fucoxanthin, chlorophyll a/c-binding protein gene (FCP). In these cotransformants, LUC activity was light inducible. The transient transformation of the centric diatom Thalassiosira weissflogii with the bacterial beta-glucuronidase (GUS) gene has also been achieved using similar transformation technology. The availability of gene transfer protocols for marine diatoms, together with a range of functional reporter genes and regulated expression systems, will permit molecular dissection of their biology and allow an assessment of the biotechnological potential of these organisms.
Collapse
Affiliation(s)
- A Falciatore
- Laboratory of Molecular Plant Biology, Stazione Zoologica, Villa Comunale, I-80121 Naples, Italy
| | | | | | | | | |
Collapse
|
43
|
Limauro D, Falciatore A, Basso AL, Forlani G, De Felice M. Proline biosynthesis in Streptococcus thermophilus: characterization of the proBA operon and its products. Microbiology (Reading) 1996; 142 ( Pt 11):3275-82. [PMID: 8969524 DOI: 10.1099/13500872-142-11-3275] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The presence of proline in the medium was not essential for growth of Streptococcus thermophilus, indicating that there is a proline biosynthetic pathway in this organism. Genetic and biochemical analysis identified and characterized this pathway. Two genes, designated proB and proA, were cloned, sequenced and characterized. Biochemical analysis of the proB- and proA-encoded enzymes showed that the proline biosynthetic pathway of S. thermophilus is similar to the one previously described in Escherichia coli. The deduced amino acid sequence of a 2-408 kb DNA region containing the genes revealed the similarity of the S. thermophilus gene products to ProB and ProA of E. coli and Serratia marcescens, and to the corresponding N- and C-terminal domains of the bifunctional plant enzyme delta 1-pyrroline-5-carboxylate synthetase of Vigna aconitifolia. Northern blot analysis showed that the two genes in S. thermophilus are organized in a single operon with proB proximal and proA distal to the promoter; primer extension analysis indicated that proBA transcription is not under repressive control by exogenously supplied proline.
Collapse
Affiliation(s)
- D Limauro
- Dipartimento di Fisiologia Generale ed Ambientale, Università Federico II, Naples, Italy
| | | | | | | | | |
Collapse
|