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Yang HP, Wenzel M, Hauser DA, Nelson JM, Xu X, Eliáš M, Li FW. Monodopsis and Vischeria Genomes Shed New Light on the Biology of Eustigmatophyte Algae. Genome Biol Evol 2021; 13:6402010. [PMID: 34665222 PMCID: PMC8570151 DOI: 10.1093/gbe/evab233] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [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] [Accepted: 10/09/2021] [Indexed: 11/12/2022] Open
Abstract
Members of eustigmatophyte algae, especially Nannochloropsis and Microchloropsis, have been tapped for biofuel production owing to their exceptionally high lipid content. Although extensive genomic, transcriptomic, and synthetic biology toolkits have been made available for Nannochloropsis and Microchloropsis, very little is known about other eustigmatophytes. Here we present three near-chromosomal and gapless genome assemblies of Monodopsis strains C73 and C141 (60 Mb) and Vischeria strain C74 (106 Mb), which are the sister groups to Nannochloropsis and Microchloropsis in the order Eustigmatales. These genomes contain unusually high percentages of simple repeats, ranging from 12% to 21% of the total assembly size. Unlike Nannochloropsis and Microchloropsis, long interspersed nuclear element repeats are abundant in Monodopsis and Vischeria and might constitute the centromeric regions. We found that both mevalonate and nonmevalonate pathways for terpenoid biosynthesis are present in Monodopsis and Vischeria, which is different from Nannochloropsis and Microchloropsis that have only the latter. Our analysis further revealed extensive spliced leader trans-splicing in Monodopsis and Vischeria at 36-61% of genes. Altogether, the high-quality genomes of Monodopsis and Vischeria not only serve as the much-needed outgroups to advance Nannochloropsis and Microchloropsis research, but also shed new light on the biology and evolution of eustigmatophyte algae.
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Affiliation(s)
| | - Marius Wenzel
- School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | | | | | - Xia Xu
- Boyce Thompson Institute, Ithaca, New York, USA
| | - Marek Eliáš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Fay-Wei Li
- Boyce Thompson Institute, Ithaca, New York, USA.,Plant Biology Section, Cornell University, USA
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Bellan A, Bucci F, Perin G, Alboresi A, Morosinotto T. Photosynthesis Regulation in Response to Fluctuating Light in the Secondary Endosymbiont Alga Nannochloropsis gaditana. Plant Cell Physiol 2020; 61:41-52. [PMID: 31511895 DOI: 10.1093/pcp/pcz174] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [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: 06/06/2019] [Accepted: 09/03/2019] [Indexed: 06/10/2023]
Abstract
In nature, photosynthetic organisms are exposed to highly dynamic environmental conditions where the excitation energy and electron flow in the photosynthetic apparatus need to be continuously modulated. Fluctuations in incident light are particularly challenging because they drive oversaturation of photosynthesis with consequent oxidative stress and photoinhibition. Plants and algae have evolved several mechanisms to modulate their photosynthetic machinery to cope with light dynamics, such as thermal dissipation of excited chlorophyll states (non-photochemical quenching, NPQ) and regulation of electron transport. The regulatory mechanisms involved in the response to light dynamics have adapted during evolution, and exploring biodiversity is a valuable strategy for expanding our understanding of their biological roles. In this work, we investigated the response to fluctuating light in Nannochloropsis gaditana, a eukaryotic microalga of the phylum Heterokonta originating from a secondary endosymbiotic event. Nannochloropsis gaditana is negatively affected by light fluctuations, leading to large reductions in growth and photosynthetic electron transport. Exposure to light fluctuations specifically damages photosystem I, likely because of the ineffective regulation of electron transport in this species. The role of NPQ, also assessed using a mutant strain specifically depleted of this response, was instead found to be minor, especially in responding to the fastest light fluctuations.
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Affiliation(s)
- Alessandra Bellan
- Department of Biology, University of Padova, Via U. Bassi 58/B, Padova 35121, Italy
| | - Francesca Bucci
- Department of Biology, University of Padova, Via U. Bassi 58/B, Padova 35121, Italy
| | - Giorgio Perin
- Department of Biology, University of Padova, Via U. Bassi 58/B, Padova 35121, Italy
| | - Alessandro Alboresi
- Department of Biology, University of Padova, Via U. Bassi 58/B, Padova 35121, Italy
| | - Tomas Morosinotto
- Department of Biology, University of Padova, Via U. Bassi 58/B, Padova 35121, Italy
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Balzano S, Villanueva L, de Bar M, Sahonero Canavesi DX, Yildiz C, Engelmann JC, Marechal E, Lupette J, Sinninghe Damst� JS, Schouten S. Biosynthesis of Long Chain Alkyl Diols and Long Chain Alkenols in Nannochloropsis spp. (Eustigmatophyceae). Plant Cell Physiol 2019; 60:1666-1682. [PMID: 31058972 PMCID: PMC6872974 DOI: 10.1093/pcp/pcz078] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [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: 12/14/2018] [Accepted: 04/26/2019] [Indexed: 05/05/2023]
Abstract
We investigated potential biosynthetic pathways of long chain alkenols (LCAs), long chain alkyl diols (LCDs), and long chain hydroxy fatty acids (LCHFAs) in Nannochloropsis oceanica and Nannochloropsis gaditana, by combining culturing experiments with genomic and transcriptomic analyses. Incubation of Nannochloropsis spp. in the dark for 1 week led to significant increases in the cellular concentrations of LCAs and LCDs in both species. Consistently, 13C-labelled substrate experiments confirmed that both LCA and LCD were actively produced in the dark from C14-18 fatty acids by either condensation or elongation/hydroxylation, although no enzymatic evidence was found for the former pathway. Nannochloropsis spp. did, however, contain (i) multiple polyketide synthases (PKSs) including one type (PKS-Clade II) that might catalyze incomplete fatty acid elongations leading to the formation of 3-OH-fatty acids, (ii) 3-hydroxyacyl dehydratases (HADs), which can possibly form Δ2/Δ3 monounsaturated fatty acids, and (iii) fatty acid elongases (FAEs) that could elongate 3-OH-fatty acids and Δ2/Δ3 monounsaturated fatty acids to longer products. The enzymes responsible for reduction of the long chain fatty acids to LCDs and LCAs are, however, unclear. A putative wax ester synthase/acyl coenzyme A (acyl-CoA): diacylglycerol acyltransferase is likely to be involved in the esterification of LCAs and LCDs in the cell wall. Our data thus provide useful insights in predicting the biosynthetic pathways of LCAs and LCDs in phytoplankton suggesting a key role of FAE and PKS enzymes.
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Affiliation(s)
- Sergio Balzano
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
- Corresponding author: E-mail, ; Fax, +39 081 7641355. Present address: Stazione Zoologica Anton Dohrn, Istituto Nazionale di Biologia Ecologia e Biotecnologie Marine, Villa Comunale, Napoli, Italy
| | - Laura Villanueva
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
| | - Marijke de Bar
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
| | - Diana X Sahonero Canavesi
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
| | - Caglar Yildiz
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
| | - Julia C Engelmann
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
| | - Eric Marechal
- Laboratoire de Physiologie Cellulaire et V�g�tale, Unit� mixte de recherche CNRS, CEA, INRA, Universit� Grenoble Alpes, CEA Grenoble, 17 Avenue des Martyrs, Grenoble, France
| | - Josselin Lupette
- Laboratoire de Physiologie Cellulaire et V�g�tale, Unit� mixte de recherche CNRS, CEA, INRA, Universit� Grenoble Alpes, CEA Grenoble, 17 Avenue des Martyrs, Grenoble, France
- Present address: MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Jaap S Sinninghe Damst�
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
| | - Stefan Schouten
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
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