1
|
Düner M, Lambertz J, Mügge C, Hemschemeier A. The soluble guanylate cyclase CYG12 is required for the acclimation to hypoxia and trophic regimes in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 93:311-337. [PMID: 29161457 DOI: 10.1111/tpj.13779] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 11/03/2017] [Accepted: 11/09/2017] [Indexed: 05/27/2023]
Abstract
Oxygenic phototrophs frequently encounter environmental conditions that result in intracellular energy crises. Growth of the unicellular green alga Chlamydomonas reinhardtii in hypoxia in the light depends on acclimatory responses of which the induction of photosynthetic cyclic electron flow is essential. The microalga cannot grow in the absence of molecular oxygen (O2 ) in the dark, although it possesses an elaborate fermentation metabolism. Not much is known about how the microalga senses and signals the lack of O2 or about its survival strategies during energy crises. Recently, nitric oxide (NO) has emerged to be required for the acclimation of C. reinhardtii to hypoxia. In this study, we show that the soluble guanylate cyclase (sGC) CYG12, a homologue of animal NO sensors, is also involved in this response. CYG12 is an active sGC, and post-transcriptional down-regulation of the CYG12 gene impairs hypoxic growth and gene expression in C. reinhardtii. However, it also results in a disturbed photosynthetic apparatus under standard growth conditions and the inability to grow heterotrophically. Transcriptome profiles indicate that the mis-expression of CYG12 results in a perturbation of responses that, in the wild-type, maintain the cellular energy budget. We suggest that CYG12 is required for the proper operation of the photosynthetic apparatus which, in turn, is essential for survival in hypoxia and darkness.
Collapse
Affiliation(s)
- Melis Düner
- Department of Plant Biochemistry, Workgroup Photobiotechnology, Faculty of Biology and Biotechnology, Ruhr-University of Bochum, Universitätsstr. 150, 44801, Bochum, Germany
| | - Jan Lambertz
- Department of Plant Biochemistry, Workgroup Photobiotechnology, Faculty of Biology and Biotechnology, Ruhr-University of Bochum, Universitätsstr. 150, 44801, Bochum, Germany
| | - Carolin Mügge
- Junior Research Group for Microbial Biotechnology, Faculty of Biology and Biotechnology, Ruhr-University of Bochum, Universitätsstr. 150, 44801, Bochum, Germany
| | - Anja Hemschemeier
- Department of Plant Biochemistry, Workgroup Photobiotechnology, Faculty of Biology and Biotechnology, Ruhr-University of Bochum, Universitätsstr. 150, 44801, Bochum, Germany
| |
Collapse
|
2
|
Fan G, Niu S, Zhao Z, Deng M, Xu E, Wang Y, Yang L. Identification of microRNAs and their targets in Paulownia fortunei plants free from phytoplasma pathogen after methyl methane sulfonate treatment. Biochimie 2016; 127:271-80. [PMID: 27328782 DOI: 10.1016/j.biochi.2016.06.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 06/15/2016] [Indexed: 12/28/2022]
Abstract
MicroRNAs (miRNAs) play major roles in plant responses to various biotic and abiotic stresses by regulating gene expression at the transcriptional and post-transcriptional levels. Paulownia witches' broom (PaWB) disease caused by phytoplasmas reduces Paulownia production worldwide. In this study, we investigated the miRNA-mediated plant response to PaWB phytoplasma by Illumina sequencing and degradome analysis of Paulownia fortunei small RNAs (sRNAs). The sRNA and degradome libraries were constructed from healthy and diseased P. fortunei plants and the plants free from phytoplasma pathogen after 60 mg L(-1) methyl methane sulfonate treatment. A total of 96 P. fortunei-conserved miRNAs and 83 putative novel miRNAs were identified. Among them, 37 miRNAs (17 conserved, 20 novel) were found to be differentially expressed in response to PaWB phytoplasma infection. In addition, 114 target genes for 18 of the conserved miRNA families and 33 target genes for 15 of the novel miRNAs in P. fortunei were detected. The expression patterns of 14 of the PaWB phytoplasma-responsive miRNAs and 12 target genes were determined by quantitative real-time polymerase chain reaction (qPCR) experiments. A functional analysis of the miRNA targets indicated that these targeted genes may regulate transcription, stress response, nitrogen metabolism, and various other activities. Our results will help identify the potential roles of miRNAs involved in protecting P. fortunei from diseases.
Collapse
Affiliation(s)
- Guoqiang Fan
- Institute of Paulownia, Henan Agricultural University, 450002 Zhengzhou, Henan, PR China; College of Forestry, Henan Agricultural University, 450002 Zhengzhou, Henan, PR China.
| | - Suyan Niu
- Institute of Paulownia, Henan Agricultural University, 450002 Zhengzhou, Henan, PR China; College of Forestry, Henan Agricultural University, 450002 Zhengzhou, Henan, PR China
| | - Zhenli Zhao
- Institute of Paulownia, Henan Agricultural University, 450002 Zhengzhou, Henan, PR China; College of Forestry, Henan Agricultural University, 450002 Zhengzhou, Henan, PR China
| | - Minjie Deng
- Institute of Paulownia, Henan Agricultural University, 450002 Zhengzhou, Henan, PR China; College of Forestry, Henan Agricultural University, 450002 Zhengzhou, Henan, PR China
| | - Enkai Xu
- Institute of Paulownia, Henan Agricultural University, 450002 Zhengzhou, Henan, PR China; College of Forestry, Henan Agricultural University, 450002 Zhengzhou, Henan, PR China
| | - Yuanlong Wang
- Institute of Paulownia, Henan Agricultural University, 450002 Zhengzhou, Henan, PR China; College of Forestry, Henan Agricultural University, 450002 Zhengzhou, Henan, PR China
| | - Lu Yang
- Institute of Paulownia, Henan Agricultural University, 450002 Zhengzhou, Henan, PR China; College of Forestry, Henan Agricultural University, 450002 Zhengzhou, Henan, PR China
| |
Collapse
|
3
|
Burgess SJ, Taha H, Yeoman JA, Iamshanova O, Chan KX, Boehm M, Behrends V, Bundy JG, Bialek W, Murray JW, Nixon PJ. Identification of the Elusive Pyruvate Reductase of Chlamydomonas reinhardtii Chloroplasts. PLANT & CELL PHYSIOLOGY 2016; 57:82-94. [PMID: 26574578 PMCID: PMC4722173 DOI: 10.1093/pcp/pcv167] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 10/27/2015] [Indexed: 05/19/2023]
Abstract
Under anoxic conditions the green alga Chlamydomonas reinhardtii activates various fermentation pathways leading to the creation of formate, acetate, ethanol and small amounts of other metabolites including d-lactate and hydrogen. Progress has been made in identifying the enzymes involved in these pathways and their subcellular locations; however, the identity of the enzyme involved in reducing pyruvate to d-lactate has remained unclear. Based on sequence comparisons, enzyme activity measurements, X-ray crystallography, biochemical fractionation and analysis of knock-down mutants, we conclude that pyruvate reduction in the chloroplast is catalyzed by a tetrameric NAD(+)-dependent d-lactate dehydrogenase encoded by Cre07.g324550. Its expression during aerobic growth supports a possible function as a 'lactate valve' for the export of lactate to the mitochondrion for oxidation by cytochrome-dependent d-lactate dehydrogenases and by glycolate dehydrogenase. We also present a revised spatial model of fermentation based on our immunochemical detection of the likely pyruvate decarboxylase, PDC3, in the cytoplasm.
Collapse
Affiliation(s)
- Steven J Burgess
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK These authors contributed equally to this work
| | - Hussein Taha
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK These authors contributed equally to this work Present address: Faculty of Science, Universiti Brunei Darussalam, Jalan Tungku Link, BE1410, Brunei Darussalam
| | - Justin A Yeoman
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Oksana Iamshanova
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Kher Xing Chan
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Marko Boehm
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Volker Behrends
- Department of Biomolecular Medicine, Sir Alexander Fleming Building, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Jacob G Bundy
- Department of Biomolecular Medicine, Sir Alexander Fleming Building, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Wojciech Bialek
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - James W Murray
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Peter J Nixon
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| |
Collapse
|
4
|
Antal TK, Krendeleva TE, Tyystjärvi E. Multiple regulatory mechanisms in the chloroplast of green algae: relation to hydrogen production. PHOTOSYNTHESIS RESEARCH 2015; 125:357-81. [PMID: 25986411 DOI: 10.1007/s11120-015-0157-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Accepted: 05/11/2015] [Indexed: 05/10/2023]
Abstract
A complex regulatory network in the chloroplast of green algae provides an efficient tool for maintenance of energy and redox balance in the cell under aerobic and anaerobic conditions. In this review, we discuss the structural and functional organizations of electron transport pathways in the chloroplast, and regulation of photosynthesis in the green microalga Chlamydomonas reinhardtii. The focus is on the regulatory mechanisms induced in response to nutrient deficiency stress and anoxia and especially on the role of a hydrogenase-mediated reaction in adaptation to highly reducing conditions and ATP deficiency in the cell.
Collapse
Affiliation(s)
- Taras K Antal
- Faculty of Biology, Moscow State University, Vorobyevi Gory, Moscow, 119992, Russia,
| | | | | |
Collapse
|
5
|
Discovery of microRNAs and transcript targets related to witches' broom disease in Paulownia fortunei by high-throughput sequencing and degradome approach. Mol Genet Genomics 2015; 291:181-91. [PMID: 26243687 DOI: 10.1007/s00438-015-1102-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 07/28/2015] [Indexed: 10/23/2022]
Abstract
Paulownia witches' broom (PaWB) caused by the phytoplasma is a devastating disease of Paulownia trees. It has caused heavy yield losses to Paulownia production worldwide. However, knowledge of the transcriptional and post-transcriptional regulation of gene expression by microRNAs (miRNAs), especially miRNAs responsive to PaWB disease stress, is still rudimentary. In this study, to identify miRNAs and their transcript targets that are responsive to PaWB disease stress, six sequencing libraries were constructed from healthy (PF), PaWB-infected (PFI), and PaWB-infected, 20 mg L(-1) methyl methane sulfonate-treated (PFI20) P. fortunei seedlings. As a result, 95 conserved miRNAs belonging to 18 miRNA families, as well as 122 potential novel miRNAs, were identified. Most of them were found to be a response to PaWB disease-induced stress, and the expression levels of these miRNAs were validated by quantitative real-time PCR analysis. The study simultaneously identified 109 target genes from the P. fortunei for 14 conserved miRNA families and 24 novel miRNAs by degradome sequencing. Furthermore, the functions of the miRNA targets were annotated based on Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis. The results presented here provide the groundwork for further analysis of miRNAs and target genes responsive to the PaWB disease stress, and could be also useful for addressing new questions to better understand the mechanisms of plant infection by phytoplasma in the future.
Collapse
|
6
|
Yang W, Catalanotti C, Wittkopp TM, Posewitz MC, Grossman AR. Algae after dark: mechanisms to cope with anoxic/hypoxic conditions. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 82:481-503. [PMID: 25752440 DOI: 10.1111/tpj.12823] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 02/28/2015] [Accepted: 03/03/2015] [Indexed: 06/04/2023]
Abstract
Chlamydomonas reinhardtii is a unicellular, soil-dwelling (and aquatic) green alga that has significant metabolic flexibility for balancing redox equivalents and generating ATP when it experiences hypoxic/anoxic conditions. The diversity of pathways available to ferment sugars is often revealed in mutants in which the activities of specific branches of fermentative metabolism have been eliminated; compensatory pathways that have little activity in parental strains under standard laboratory fermentative conditions are often activated. The ways in which these pathways are regulated and integrated have not been extensively explored. In this review, we primarily discuss the intricacies of dark anoxic metabolism in Chlamydomonas, but also discuss aspects of dark oxic metabolism, the utilization of acetate, and the relatively uncharacterized but critical interactions that link chloroplastic and mitochondrial metabolic networks.
Collapse
Affiliation(s)
- Wenqiang Yang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Claudia Catalanotti
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Tyler M Wittkopp
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - Matthew C Posewitz
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO, 80401, USA
| | - Arthur R Grossman
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| |
Collapse
|
7
|
D'Adamo S, Jinkerson RE, Boyd ES, Brown SL, Baxter BK, Peters JW, Posewitz MC. Evolutionary and biotechnological implications of robust hydrogenase activity in halophilic strains of Tetraselmis. PLoS One 2014; 9:e85812. [PMID: 24465722 PMCID: PMC3897525 DOI: 10.1371/journal.pone.0085812] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 12/02/2013] [Indexed: 11/19/2022] Open
Abstract
Although significant advances in H2 photoproduction have recently been realized in fresh water algae (e.g. Chlamydomonas reinhardtii), relatively few studies have focused on H2 production and hydrogenase adaptations in marine or halophilic algae. Salt water organisms likely offer several advantages for biotechnological H2 production due to the global abundance of salt water, decreased H2 and O2 solubility in saline and hypersaline systems, and the ability of extracellular NaCl levels to influence metabolism. We screened unialgal isolates obtained from hypersaline ecosystems in the southwest United States and identified two distinct halophilic strains of the genus Tetraselmis (GSL1 and QNM1) that exhibit both robust fermentative and photo H2-production activities. The influence of salinity (3.5%, 5.5% and 7.0% w/v NaCl) on H2 production was examined during anoxic acclimation, with the greatest in vivo H2-production rates observed at 7.0% NaCl. These Tetraselmis strains maintain robust hydrogenase activity even after 24 h of anoxic acclimation and show increased hydrogenase activity relative to C. reinhardtii after extended anoxia. Transcriptional analysis of Tetraselmis GSL1 enabled sequencing of the cDNA encoding the FeFe-hydrogenase structural enzyme (HYDA) and its maturation proteins (HYDE, HYDEF and HYDG). In contrast to freshwater Chlorophyceae, the halophilic Tetraselmis GSL1 strain likely encodes a single HYDA and two copies of HYDE, one of which is fused to HYDF. Phylogenetic analyses of HYDA and concatenated HYDA, HYDE, HYDF and HYDG in Tetraselmis GSL1 fill existing knowledge gaps in the evolution of algal hydrogenases and indicate that the algal hydrogenases sequenced to date are derived from a common ancestor. This is consistent with recent hypotheses that suggest fermentative metabolism in the majority of eukaryotes is derived from a common base set of enzymes that emerged early in eukaryotic evolution with subsequent losses in some organisms.
Collapse
Affiliation(s)
- Sarah D'Adamo
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, Colorado, United States of America
| | - Robert E. Jinkerson
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, Colorado, United States of America
| | - Eric S. Boyd
- Department of Microbiology and the Thermal Biology Institute, Montana State University, Bozeman, Montana, United States of America
| | - Susan L. Brown
- Center for Marine Microbial Ecology and Diversity, University of Hawaii, Honolulu, Hawaii, United States of America
| | - Bonnie K. Baxter
- Department of Biology and the Great Salt Lake Institute, Westminster College, Salt Lake City, Utah, United States of America
| | - John W. Peters
- Department of Microbiology and the Thermal Biology Institute, Montana State University, Bozeman, Montana, United States of America
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, United States of America
| | - Matthew C. Posewitz
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, Colorado, United States of America
| |
Collapse
|
8
|
Höhner R, Barth J, Magneschi L, Jaeger D, Niehues A, Bald T, Grossman A, Fufezan C, Hippler M. The metabolic status drives acclimation of iron deficiency responses in Chlamydomonas reinhardtii as revealed by proteomics based hierarchical clustering and reverse genetics. Mol Cell Proteomics 2013; 12:2774-90. [PMID: 23820728 PMCID: PMC3790290 DOI: 10.1074/mcp.m113.029991] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 06/04/2013] [Indexed: 11/06/2022] Open
Abstract
Iron is a crucial cofactor in numerous redox-active proteins operating in bioenergetic pathways including respiration and photosynthesis. Cellular iron management is essential to sustain sufficient energy production and minimize oxidative stress. To produce energy for cell growth, the green alga Chlamydomonas reinhardtii possesses the metabolic flexibility to use light and/or carbon sources such as acetate. To investigate the interplay between the iron-deficiency response and growth requirements under distinct trophic conditions, we took a quantitative proteomics approach coupled to innovative hierarchical clustering using different "distance-linkage combinations" and random noise injection. Protein co-expression analyses of the combined data sets revealed insights into cellular responses governing acclimation to iron deprivation and regulation associated with photosynthesis dependent growth. Photoautotrophic growth requirements as well as the iron deficiency induced specific metabolic enzymes and stress related proteins, and yet differences in the set of induced enzymes, proteases, and redox-related polypeptides were evident, implying the establishment of distinct response networks under the different conditions. Moreover, our data clearly support the notion that the iron deficiency response includes a hierarchy for iron allocation within organelles in C. reinhardtii. Importantly, deletion of a bifunctional alcohol and acetaldehyde dehydrogenase (ADH1), which is induced under low iron based on the proteomic data, attenuates the remodeling of the photosynthetic machinery in response to iron deficiency, and at the same time stimulates expression of stress-related proteins such as NDA2, LHCSR3, and PGRL1. This finding provides evidence that the coordinated regulation of bioenergetics pathways and iron deficiency response is sensitive to the cellular and chloroplast metabolic and/or redox status, consistent with systems approach data.
Collapse
Affiliation(s)
- Ricarda Höhner
- From the ‡Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster 48143, Germany
| | - Johannes Barth
- From the ‡Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster 48143, Germany
| | - Leonardo Magneschi
- From the ‡Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster 48143, Germany
| | - Daniel Jaeger
- From the ‡Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster 48143, Germany
| | - Anna Niehues
- From the ‡Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster 48143, Germany
| | - Till Bald
- From the ‡Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster 48143, Germany
| | - Arthur Grossman
- §Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Christian Fufezan
- From the ‡Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster 48143, Germany
| | - Michael Hippler
- From the ‡Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, Münster 48143, Germany
| |
Collapse
|
9
|
Banti V, Giuntoli B, Gonzali S, Loreti E, Magneschi L, Novi G, Paparelli E, Parlanti S, Pucciariello C, Santaniello A, Perata P. Low oxygen response mechanisms in green organisms. Int J Mol Sci 2013; 14:4734-61. [PMID: 23446868 PMCID: PMC3634410 DOI: 10.3390/ijms14034734] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 02/20/2013] [Accepted: 02/21/2013] [Indexed: 01/04/2023] Open
Abstract
Low oxygen stress often occurs during the life of green organisms, mostly due to the environmental conditions affecting oxygen availability. Both plants and algae respond to low oxygen by resetting their metabolism. The shift from mitochondrial respiration to fermentation is the hallmark of anaerobic metabolism in most organisms. This involves a modified carbohydrate metabolism coupled with glycolysis and fermentation. For a coordinated response to low oxygen, plants exploit various molecular mechanisms to sense when oxygen is either absent or in limited amounts. In Arabidopsis thaliana, a direct oxygen sensing system has recently been discovered, where a conserved N-terminal motif on some ethylene responsive factors (ERFs), targets the fate of the protein under normoxia/hypoxia. In Oryza sativa, this same group of ERFs drives physiological and anatomical modifications that vary in relation to the genotype studied. The microalga Chlamydomonas reinhardtii responses to low oxygen seem to have evolved independently of higher plants, posing questions on how the fermentative metabolism is modulated. In this review, we summarize the most recent findings related to these topics, highlighting promising developments for the future.
Collapse
Affiliation(s)
- Valeria Banti
- PlantLab, Institute of Life Sciences, Scuola Superiore Sant’Anna, Via Mariscoglio 34, Pisa 56124, Italy; E-Mails: (V.B.); (B.G.); (S.G.); (G.N.); (E.P.); (S.P.); (C.P.); (A.S.)
| | - Beatrice Giuntoli
- PlantLab, Institute of Life Sciences, Scuola Superiore Sant’Anna, Via Mariscoglio 34, Pisa 56124, Italy; E-Mails: (V.B.); (B.G.); (S.G.); (G.N.); (E.P.); (S.P.); (C.P.); (A.S.)
| | - Silvia Gonzali
- PlantLab, Institute of Life Sciences, Scuola Superiore Sant’Anna, Via Mariscoglio 34, Pisa 56124, Italy; E-Mails: (V.B.); (B.G.); (S.G.); (G.N.); (E.P.); (S.P.); (C.P.); (A.S.)
| | - Elena Loreti
- Institute of Agricultural Biology and Biotechnology, National Research Council, Via Moruzzi 1, Pisa 56100, Italy; E-Mail:
| | - Leonardo Magneschi
- Institute of Plant Biochemistry and Biotechnology, University of Münster, Schlossplatz 8, Münster 48143, Germany; E-Mail:
| | - Giacomo Novi
- PlantLab, Institute of Life Sciences, Scuola Superiore Sant’Anna, Via Mariscoglio 34, Pisa 56124, Italy; E-Mails: (V.B.); (B.G.); (S.G.); (G.N.); (E.P.); (S.P.); (C.P.); (A.S.)
| | - Eleonora Paparelli
- PlantLab, Institute of Life Sciences, Scuola Superiore Sant’Anna, Via Mariscoglio 34, Pisa 56124, Italy; E-Mails: (V.B.); (B.G.); (S.G.); (G.N.); (E.P.); (S.P.); (C.P.); (A.S.)
| | - Sandro Parlanti
- PlantLab, Institute of Life Sciences, Scuola Superiore Sant’Anna, Via Mariscoglio 34, Pisa 56124, Italy; E-Mails: (V.B.); (B.G.); (S.G.); (G.N.); (E.P.); (S.P.); (C.P.); (A.S.)
| | - Chiara Pucciariello
- PlantLab, Institute of Life Sciences, Scuola Superiore Sant’Anna, Via Mariscoglio 34, Pisa 56124, Italy; E-Mails: (V.B.); (B.G.); (S.G.); (G.N.); (E.P.); (S.P.); (C.P.); (A.S.)
| | - Antonietta Santaniello
- PlantLab, Institute of Life Sciences, Scuola Superiore Sant’Anna, Via Mariscoglio 34, Pisa 56124, Italy; E-Mails: (V.B.); (B.G.); (S.G.); (G.N.); (E.P.); (S.P.); (C.P.); (A.S.)
| | - Pierdomenico Perata
- PlantLab, Institute of Life Sciences, Scuola Superiore Sant’Anna, Via Mariscoglio 34, Pisa 56124, Italy; E-Mails: (V.B.); (B.G.); (S.G.); (G.N.); (E.P.); (S.P.); (C.P.); (A.S.)
| |
Collapse
|
10
|
Swirsky Whitney LA, Novi G, Perata P, Loreti E. Distinct mechanisms regulating gene expression coexist within the fermentative pathways in Chlamydomonas reinhardtii. ScientificWorldJournal 2012; 2012:565047. [PMID: 22792045 PMCID: PMC3385630 DOI: 10.1100/2012/565047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 03/21/2012] [Indexed: 12/12/2022] Open
Abstract
Under dark anoxia, the unicellular green algae Chlamydomonas reinhardtii may produce hydrogen by means of its hydrogenase enzymes, in particular HYD1, using reductants derived from the degradation of intercellular carbon stores. Other enzymes belonging to the fermentative pathways compete for the same reductants. A complete understanding of the mechanisms determining the activation of one pathway rather than another will help us engineer Chlamydomonas for fermentative metabolite production, including hydrogen. We examined the expression pattern of the fermentative genes PDC3, LDH1, ADH2, PFL1, and PFR1 in response to day-night cycles, continuous light, continuous darkness, and low or high oxygen availability, which are all conditions that vary on a regular basis in Chlamydomonas' natural environment. We found that all genes except PFL1 show daily fluctuations in expression, and that PFR1 differentiated itself from the others in that it is clearly responsive to low oxygen, where as PDC3, LDH1, and ADH2 are primarily under diurnal regulation. Our results provide evidence that there exist at least three different regulatory mechanisms within the fermentative pathways and suggest that the fermentative pathways are not redundant but rather that availability of a variety of pathways allows for a differential metabolic response to different environmental conditions.
Collapse
|
11
|
Magneschi L, Catalanotti C, Subramanian V, Dubini A, Yang W, Mus F, Posewitz MC, Seibert M, Perata P, Grossman AR. A mutant in the ADH1 gene of Chlamydomonas reinhardtii elicits metabolic restructuring during anaerobiosis. PLANT PHYSIOLOGY 2012; 158:1293-305. [PMID: 22271746 PMCID: PMC3291268 DOI: 10.1104/pp.111.191569] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 01/21/2012] [Indexed: 05/20/2023]
Abstract
The green alga Chlamydomonas reinhardtii has numerous genes encoding enzymes that function in fermentative pathways. Among these, the bifunctional alcohol/acetaldehyde dehydrogenase (ADH1), highly homologous to the Escherichia coli AdhE enzyme, is proposed to be a key component of fermentative metabolism. To investigate the physiological role of ADH1 in dark anoxic metabolism, a Chlamydomonas adh1 mutant was generated. We detected no ethanol synthesis in this mutant when it was placed under anoxia; the two other ADH homologs encoded on the Chlamydomonas genome do not appear to participate in ethanol production under our experimental conditions. Pyruvate formate lyase, acetate kinase, and hydrogenase protein levels were similar in wild-type cells and the adh1 mutant, while the mutant had significantly more pyruvate:ferredoxin oxidoreductase. Furthermore, a marked change in metabolite levels (in addition to ethanol) synthesized by the mutant under anoxic conditions was observed; formate levels were reduced, acetate levels were elevated, and the production of CO(2) was significantly reduced, but fermentative H(2) production was unchanged relative to wild-type cells. Of particular interest is the finding that the mutant accumulates high levels of extracellular glycerol, which requires NADH as a substrate for its synthesis. Lactate production is also increased slightly in the mutant relative to the control strain. These findings demonstrate a restructuring of fermentative metabolism in the adh1 mutant in a way that sustains the recycling (oxidation) of NADH and the survival of the mutant (similar to wild-type cell survival) during dark anoxic growth.
Collapse
Affiliation(s)
- Leonardo Magneschi
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Terashima M, Specht M, Hippler M. The chloroplast proteome: a survey from the Chlamydomonas reinhardtii perspective with a focus on distinctive features. Curr Genet 2011; 57:151-68. [PMID: 21533645 DOI: 10.1007/s00294-011-0339-1] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 04/05/2011] [Accepted: 04/07/2011] [Indexed: 01/12/2023]
Abstract
The unicellular green alga Chlamydomonas reinhardtii has emerged to be an important model organism for the study of oxygenic eukaryotic photosynthesis as well as other processes occurring in the chloroplast. However, the chloroplast proteome in C. reinhardtii has only recently been comprehensively characterized, made possible by proteomics emerging as an accessible and powerful tool over the last decade. In this review, we introduce a compiled list of 996 experimentally chloroplast-localized proteins for C. reinhardtii, stemming largely from our previous proteomic dataset comparing chloroplasts and mitochondria samples to localize proteins. In order to get a taste of some cellular functions taking place in the C. reinhardtii chloroplast, we will focus this review particularly on metabolic differences between chloroplasts of C. reinhardtii and higher plants. Areas that will be covered are photosynthesis, chlorophyll biosynthesis, carbon metabolism, fermentative metabolism, ferredoxins and ferredoxin-interacting proteins.
Collapse
Affiliation(s)
- Mia Terashima
- Department of Biology, Institute of Plant Biology and Biotechnology, University of Münster, Hindenburgplatz 55, 48143, Münster, Germany
| | | | | |
Collapse
|
13
|
|