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Lihanova Y, Nagel R, Jakob T, Sasso S. Characterization of activating cis-regulatory elements from the histone genes of Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024. [PMID: 38693717 DOI: 10.1111/tpj.16781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 04/08/2024] [Accepted: 04/12/2024] [Indexed: 05/03/2024]
Abstract
Regulation of gene expression in eukaryotes is controlled by cis-regulatory modules (CRMs). A major class of CRMs are enhancers which are composed of activating cis-regulatory elements (CREs) responsible for upregulating transcription. To date, most enhancers and activating CREs have been studied in angiosperms; in contrast, our knowledge about these key regulators of gene expression in green algae is limited. In this study, we aimed at characterizing putative activating CREs/CRMs from the histone genes of the unicellular model alga Chlamydomonas reinhardtii. To test the activity of four candidates, reporter constructs consisting of a tetramerized CRE, an established promoter, and a gene for the mCerulean3 fluorescent protein were incorporated into the nuclear genome of C. reinhardtii, and their activity was quantified by flow cytometry. Two tested candidates, Eupstr and Ehist cons, significantly upregulated gene expression and were characterized in detail. Eupstr, which originates from highly expressed genes of C. reinhardtii, is an orientation-independent CRE capable of activating both the RBCS2 and β2-tubulin promoters. Ehist cons, which is a CRM from histone genes of angiosperms, upregulates the β2-tubulin promoter in C. reinhardtii over a distance of at least 1.5 kb. The octamer motif present in Ehist cons was identified in C. reinhardtii and the related green algae Chlamydomonas incerta, Chlamydomonas schloesseri, and Edaphochlamys debaryana, demonstrating its high evolutionary conservation. The results of this investigation expand our knowledge about the regulation of gene expression in green algae. Furthermore, the characterized activating CREs/CRMs can be applied as valuable genetic tools.
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Affiliation(s)
- Yuliia Lihanova
- Department of Plant Physiology, Institute of Biology, Leipzig University, Leipzig, Germany
| | - Raimund Nagel
- Department of Plant Physiology, Institute of Biology, Leipzig University, Leipzig, Germany
| | - Torsten Jakob
- Department of Plant Physiology, Institute of Biology, Leipzig University, Leipzig, Germany
| | - Severin Sasso
- Department of Plant Physiology, Institute of Biology, Leipzig University, Leipzig, Germany
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2
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Tsai TY, Chien YL, Zheng YY, Li YC, Chen JC, Su RC, Ben-Sheleg A, Khozin-Goldberg I, Vonshak A, Lee TM. Modification in the ascorbate-glutathione cycle leads to a better acclimation to high light in the rose Bengal resistant mutant of Nannochloropsis oceanica. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 207:108326. [PMID: 38237421 DOI: 10.1016/j.plaphy.2023.108326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 03/16/2024]
Abstract
Understanding how to adapt outdoor cultures of Nannochloropsis oceanica to high light (HL) is vital for boosting productivity. The N. oceanica RB2 mutant, obtained via ethyl methanesulfonate mutagenesis, was chosen for its tolerance to Rose Bengal (RB), a singlet oxygen (1O2) generator. Compared to the wild type (WT), the RB2 mutant showed higher resilience to excess light conditions. Analyzing the ascorbate-glutathione cycle (AGC), involving ascorbate peroxidases (APX, EC 1.11.1.11), dehydroascorbate reductase (DHAR, EC 1.8.5.1), and glutathione reductase (GR, EC 1.8.1.7), in the RB2 mutant under HL stress provided valuable insights. At 250 μmol photon m-2 s-1 (HL), the WT strain displayed superoxide anion radicals (O2▪-) and hydrogen peroxide (H2O2) accumulation, increased lipid peroxidation, and cell death compared to normal light (NL) conditions (50 μmol photon m-2 s-1). The RB2 mutant didn't accumulate O2▪- and H2O2 after HL exposure, and exhibited increased APX, DHAR, and GR activities and transcript levels compared to WT and remained consistent after HL treatment. Although the RB2 mutant had a smaller ascorbate (AsA) pool than the WT, its ability to regenerate dehydroascorbate (DHA) increased post HL exposure, indicated by a higher AsA/DHA ratio. Additionally, under HL conditions, the RB2 mutant displayed an improved glutathione (GSH) regeneration rate (GSH/GSSG ratio) without changing the GSH pool size. Remarkably, H2O2 or menadione (a O2▪- donor) treatment induced cell death in the WT strain but not in the RB2 mutant. These findings emphasize the essential role of AGC in the RB2 mutant of Nannochloropsis in handling photo-oxidative stress.
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Affiliation(s)
- Tsung-Yu Tsai
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| | - Yi-Lin Chien
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| | - Yu-Yun Zheng
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| | - Yu-Chia Li
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| | - Jen-Chih Chen
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan
| | - Ruey-Chih Su
- Department of Life Science, Fu-Jen University, New Taipei City 242, Taiwan
| | - Avraham Ben-Sheleg
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion 8499000, Israel
| | - Inna Khozin-Goldberg
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion 8499000, Israel.
| | - Avigad Vonshak
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion 8499000, Israel.
| | - Tse-Min Lee
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 804, Taiwan; Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan; Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University, Kaohsiung 804, Taiwan.
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3
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Sevilla F, Martí MC, De Brasi-Velasco S, Jiménez A. Redox regulation, thioredoxins, and glutaredoxins in retrograde signalling and gene transcription. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:5955-5969. [PMID: 37453076 PMCID: PMC10575703 DOI: 10.1093/jxb/erad270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 07/12/2023] [Indexed: 07/18/2023]
Abstract
Integration of reactive oxygen species (ROS)-mediated signal transduction pathways via redox sensors and the thiol-dependent signalling network is of increasing interest in cell biology for their implications in plant growth and productivity. Redox regulation is an important point of control in protein structure, interactions, cellular location, and function, with thioredoxins (TRXs) and glutaredoxins (GRXs) being key players in the maintenance of cellular redox homeostasis. The crosstalk between second messengers, ROS, thiol redox signalling, and redox homeostasis-related genes controls almost every aspect of plant development and stress response. We review the emerging roles of TRXs and GRXs in redox-regulated processes interacting with other cell signalling systems such as organellar retrograde communication and gene expression, especially in plants during their development and under stressful environments. This approach will cast light on the specific role of these proteins as redox signalling components, and their importance in different developmental processes during abiotic stress.
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Affiliation(s)
- Francisca Sevilla
- Abiotic Stress, Production and Quality Laboratory, Department of Stress Biology and Plant Pathology, CEBAS-CSIC, Murcia, Spain
| | - Maria Carmen Martí
- Abiotic Stress, Production and Quality Laboratory, Department of Stress Biology and Plant Pathology, CEBAS-CSIC, Murcia, Spain
| | - Sabrina De Brasi-Velasco
- Abiotic Stress, Production and Quality Laboratory, Department of Stress Biology and Plant Pathology, CEBAS-CSIC, Murcia, Spain
| | - Ana Jiménez
- Abiotic Stress, Production and Quality Laboratory, Department of Stress Biology and Plant Pathology, CEBAS-CSIC, Murcia, Spain
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4
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Milito A, Aschern M, McQuillan JL, Yang JS. Challenges and advances towards the rational design of microalgal synthetic promoters in Chlamydomonas reinhardtii. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:3833-3850. [PMID: 37025006 DOI: 10.1093/jxb/erad100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 03/24/2023] [Indexed: 06/19/2023]
Abstract
Microalgae hold enormous potential to provide a safe and sustainable source of high-value compounds, acting as carbon-fixing biofactories that could help to mitigate rapidly progressing climate change. Bioengineering microalgal strains will be key to optimizing and modifying their metabolic outputs, and to render them competitive with established industrial biotechnology hosts, such as bacteria or yeast. To achieve this, precise and tuneable control over transgene expression will be essential, which would require the development and rational design of synthetic promoters as a key strategy. Among green microalgae, Chlamydomonas reinhardtii represents the reference species for bioengineering and synthetic biology; however, the repertoire of functional synthetic promoters for this species, and for microalgae generally, is limited in comparison to other commercial chassis, emphasizing the need to expand the current microalgal gene expression toolbox. Here, we discuss state-of-the-art promoter analyses, and highlight areas of research required to advance synthetic promoter development in C. reinhardtii. In particular, we exemplify high-throughput studies performed in other model systems that could be applicable to microalgae, and propose novel approaches to interrogating algal promoters. We lastly outline the major limitations hindering microalgal promoter development, while providing novel suggestions and perspectives for how to overcome them.
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Affiliation(s)
- Alfonsina Milito
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, Bellaterra, Barcelona, Spain
| | - Moritz Aschern
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, Bellaterra, Barcelona, Spain
| | - Josie L McQuillan
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK
| | - Jae-Seong Yang
- Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB, Bellaterra, Barcelona, Spain
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5
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Youssef WA, Feil R, Saint-Sorny M, Johnson X, Lunn JE, Grimm B, Brzezowski P. Singlet oxygen-induced signalling depends on the metabolic status of the Chlamydomonas reinhardtii cell. Commun Biol 2023; 6:529. [PMID: 37193883 DOI: 10.1038/s42003-023-04872-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 04/24/2023] [Indexed: 05/18/2023] Open
Abstract
Using a mutant screen, we identified trehalose 6-phosphate phosphatase 1 (TSPP1) as a functional enzyme dephosphorylating trehalose 6-phosphate (Tre6P) to trehalose in Chlamydomonas reinhardtii. The tspp1 knock-out results in reprogramming of the cell metabolism via altered transcriptome. As a secondary effect, tspp1 also shows impairment in 1O2-induced chloroplast retrograde signalling. From transcriptomic analysis and metabolite profiling, we conclude that accumulation or deficiency of certain metabolites directly affect 1O2-signalling. 1O2-inducible GLUTATHIONE PEROXIDASE 5 (GPX5) gene expression is suppressed by increased content of fumarate and 2-oxoglutarate, intermediates in the tricarboxylic acid cycle (TCA cycle) in mitochondria and dicarboxylate metabolism in the cytosol, but also myo-inositol, involved in inositol phosphate metabolism and phosphatidylinositol signalling system. Application of another TCA cycle intermediate, aconitate, recovers 1O2-signalling and GPX5 expression in otherwise aconitate-deficient tspp1. Genes encoding known essential components of chloroplast-to-nucleus 1O2-signalling, PSBP2, MBS, and SAK1, show decreased transcript levels in tspp1, which also can be rescued by exogenous application of aconitate. We demonstrate that chloroplast retrograde signalling involving 1O2 depends on mitochondrial and cytosolic processes and that the metabolic status of the cell determines the response to 1O2.
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Affiliation(s)
- Waeil Al Youssef
- Pflanzenphysiologie, Institut für Biologie, Humboldt-Universität zu Berlin, 10115, Berlin, Germany
| | - Regina Feil
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam-Golm, Germany
| | - Maureen Saint-Sorny
- Photosynthesis and Environment Team, Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), CNRS, Institut de Biosciences et Biotechnologies d'Aix-Marseille, Aix-Marseille Université, UMR 7265, CEA Cadarache, F-13108, Saint-Paul-lez-Durance, France
| | - Xenie Johnson
- Photosynthesis and Environment Team, Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), CNRS, Institut de Biosciences et Biotechnologies d'Aix-Marseille, Aix-Marseille Université, UMR 7265, CEA Cadarache, F-13108, Saint-Paul-lez-Durance, France
| | - John E Lunn
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam-Golm, Germany
| | - Bernhard Grimm
- Pflanzenphysiologie, Institut für Biologie, Humboldt-Universität zu Berlin, 10115, Berlin, Germany
| | - Pawel Brzezowski
- Pflanzenphysiologie, Institut für Biologie, Humboldt-Universität zu Berlin, 10115, Berlin, Germany.
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Jan M, Liu Z, Rochaix JD, Sun X. Retrograde and anterograde signaling in the crosstalk between chloroplast and nucleus. FRONTIERS IN PLANT SCIENCE 2022; 13:980237. [PMID: 36119624 PMCID: PMC9478734 DOI: 10.3389/fpls.2022.980237] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 08/18/2022] [Indexed: 06/02/2023]
Abstract
The chloroplast is a complex cellular organelle that not only performs photosynthesis but also synthesizes amino acids, lipids, and phytohormones. Nuclear and chloroplast genetic activity are closely coordinated through signaling chains from the nucleus to chloroplast, referred to as anterograde signaling, and from chloroplast to the nucleus, named retrograde signaling. The chloroplast can act as an environmental sensor and communicates with other cell compartments during its biogenesis and in response to stress, notably with the nucleus through retrograde signaling to regulate nuclear gene expression in response to developmental cues and stresses that affect photosynthesis and growth. Although several components involved in the generation and transmission of plastid-derived retrograde signals and in the regulation of the responsive nuclear genes have been identified, the plastid retrograde signaling network is still poorly understood. Here, we review the current knowledge on multiple plastid retrograde signaling pathways, and on potential plastid signaling molecules. We also discuss the retrograde signaling-dependent regulation of nuclear gene expression within the frame of a multilayered network of transcription factors.
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Affiliation(s)
- Masood Jan
- State Key Laboratory of Cotton Biology and State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Zhixin Liu
- State Key Laboratory of Cotton Biology and State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Jean-David Rochaix
- Department of Molecular Biology and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Xuwu Sun
- State Key Laboratory of Cotton Biology and State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
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7
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β-Cyclocitral Does Not Contribute to Singlet Oxygen-Signalling in Algae, but May Down-Regulate Chlorophyll Synthesis. PLANTS 2022; 11:plants11162155. [PMID: 36015457 PMCID: PMC9415740 DOI: 10.3390/plants11162155] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 08/09/2022] [Accepted: 08/15/2022] [Indexed: 11/16/2022]
Abstract
Light stress signalling in algae and plants is partially orchestrated by singlet oxygen (1O2), a reactive oxygen species (ROS) that causes significant damage within the chloroplast, such as lipid peroxidation. In the vicinity of the photosystem II reaction centre, a major source of 1O2, are two β-carotene molecules that quench 1O2 to ground-state oxygen. 1O2 can oxidise β-carotene to release β-cyclocitral, which has emerged as a 1O2-mediated stress signal in the plant Arabidopsis thaliana. We investigated if β-cyclocitral can have similar retrograde signalling properties in the unicellular alga Chlamydomonas reinhardtii. Using RNA-Seq, we show that genes up-regulated in response to exogenous β-cyclocitral included CAROTENOID CLEAVAGE DIOXYGENASE 8 (CCD8), while down-regulated genes included those associated with porphyrin and chlorophyll anabolism, such as tetrapyrrole-binding protein (GUN4), magnesium chelatases (CHLI1, CHLI2, CHLD, CHLH1), light-dependent protochlorophyllide reductase (POR1), copper target 1 protein (CTH1), and coproporphyrinogen III oxidase (CPX1). Down-regulation of this pathway has also been shown in β-cyclocitral-treated A. thaliana, indicating conservation of this signalling mechanism in plants. However, in contrast to A. thaliana, a very limited overlap in differential gene expression was found in β-cyclocitral-treated and 1O2-treated C. reinhardtii. Furthermore, exogenous treatment with β-cyclocitral did not induce tolerance to 1O2. We conclude that while β-cyclocitral may down-regulate chlorophyll synthesis, it does not seem to contribute to 1O2-mediated high light stress signalling in algae.
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Koletti A, Dervisi I, Kalloniati C, Zografaki ME, Rennenberg H, Roussis A, Flemetakis E. Selenium-binding Protein 1 (SBD1): A stress response regulator in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2022; 189:2368-2381. [PMID: 35579367 PMCID: PMC9342975 DOI: 10.1093/plphys/kiac230] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 04/04/2022] [Indexed: 05/20/2023]
Abstract
Selenium-binding proteins (SBPs) represent a ubiquitous protein family implicated in various environmental stress responses, although the exact molecular and physiological role of the SBP family remains elusive. In this work, we report the identification and characterization of CrSBD1, an SBP homolog from the model microalgae Chlamydomonas reinhardtii. Growth analysis of the C. reinhardtii sbd1 mutant strain revealed that the absence of a functional CrSBD1 resulted in increased growth under mild oxidative stress conditions, although cell viability rapidly declined at higher hydrogen peroxide (H2O2) concentrations. Furthermore, a combined global transcriptomic and metabolomic analysis indicated that the sbd1 mutant exhibited a dramatic quenching of the molecular and biochemical responses upon H2O2-induced oxidative stress when compared to the wild-type. Our results indicate that CrSBD1 represents a cell regulator, which is involved in the modulation of C. reinhardtii early responses to oxidative stress. We assert that CrSBD1 acts as a member of an extensive and conserved protein-protein interaction network including Fructose-bisphosphate aldolase 3, Cysteine endopeptidase 2, and Glutaredoxin 6 proteins, as indicated by yeast two-hybrid assays.
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Affiliation(s)
- Aikaterini Koletti
- Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, Athens 11855, Greece
| | - Irene Dervisi
- Department of Botany, Faculty of Biology, National & Kapodistrian University of Athens, Athens 15784, Greece
| | - Chrysanthi Kalloniati
- Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, Athens 11855, Greece
| | - Maria-Eleftheria Zografaki
- Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, Athens 11855, Greece
| | - Heinz Rennenberg
- Center of Molecular Ecophysiology (CMEP), College of Resources and Environment, Chongqing 400715, China
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Wakao S, Niyogi KK. Chlamydomonas as a model for reactive oxygen species signaling and thiol redox regulation in the green lineage. PLANT PHYSIOLOGY 2021; 187:687-698. [PMID: 35237823 PMCID: PMC8491031 DOI: 10.1093/plphys/kiab355] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 07/13/2021] [Indexed: 05/15/2023]
Abstract
One-sentence summary: Advances in proteomic and transcriptomic studies have made Chlamydomonas a powerful research model in redox and reactive oxygen species regulation with unique and overlapping mechanisms with plants.
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Affiliation(s)
- Setsuko Wakao
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA
- Author for communication: Senior author
| | - Krishna K. Niyogi
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA
- Howard Hughes Medical Institute, University of California, Berkeley, California 94720, USA
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10
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Tamaki S, Mochida K, Suzuki K. Diverse Biosynthetic Pathways and Protective Functions against Environmental Stress of Antioxidants in Microalgae. PLANTS (BASEL, SWITZERLAND) 2021; 10:1250. [PMID: 34205386 PMCID: PMC8234872 DOI: 10.3390/plants10061250] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/14/2021] [Accepted: 06/15/2021] [Indexed: 01/08/2023]
Abstract
Eukaryotic microalgae have been classified into several biological divisions and have evolutionarily acquired diverse morphologies, metabolisms, and life cycles. They are naturally exposed to environmental stresses that cause oxidative damage due to reactive oxygen species accumulation. To cope with environmental stresses, microalgae contain various antioxidants, including carotenoids, ascorbate (AsA), and glutathione (GSH). Carotenoids are hydrophobic pigments required for light harvesting, photoprotection, and phototaxis. AsA constitutes the AsA-GSH cycle together with GSH and is responsible for photooxidative stress defense. GSH contributes not only to ROS scavenging, but also to heavy metal detoxification and thiol-based redox regulation. The evolutionary diversity of microalgae influences the composition and biosynthetic pathways of these antioxidants. For example, α-carotene and its derivatives are specific to Chlorophyta, whereas diadinoxanthin and fucoxanthin are found in Heterokontophyta, Haptophyta, and Dinophyta. It has been suggested that AsA is biosynthesized via the plant pathway in Chlorophyta and Rhodophyta and via the Euglena pathway in Euglenophyta, Heterokontophyta, and Haptophyta. The GSH biosynthetic pathway is conserved in all biological kingdoms; however, Euglenophyta are able to synthesize an additional thiol antioxidant, trypanothione, using GSH as the substrate. In the present study, we reviewed and discussed the diversity of microalgal antioxidants, including recent findings.
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Affiliation(s)
- Shun Tamaki
- Microalgae Production Control Technology Laboratory, RIKEN Baton Zone Program, Yokohama 230-0045, Japan; (K.M.); (K.S.)
| | - Keiichi Mochida
- Microalgae Production Control Technology Laboratory, RIKEN Baton Zone Program, Yokohama 230-0045, Japan; (K.M.); (K.S.)
- RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan
- Kihara Institute for Biological Research, Yokohama City University, Yokohama 230-0045, Japan
- School of Information and Data Sciences, Nagasaki University, Nagasaki 852-8521, Japan
| | - Kengo Suzuki
- Microalgae Production Control Technology Laboratory, RIKEN Baton Zone Program, Yokohama 230-0045, Japan; (K.M.); (K.S.)
- euglena Co., Ltd., Tokyo 108-0014, Japan
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11
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Liu R, Chen T, Yin X, Xiang G, Peng J, Fu Q, Li M, Shang B, Ma H, Liu G, Wang Y, Xu Y. A Plasmopara viticola RXLR effector targets a chloroplast protein PsbP to inhibit ROS production in grapevine. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:1557-1570. [PMID: 33783031 DOI: 10.1111/tpj.15252] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 03/02/2021] [Accepted: 03/22/2021] [Indexed: 06/12/2023]
Abstract
Pathogens secrete a large number of effectors that manipulate host processes to create an environment conducive to pathogen colonization. However, the underlying mechanisms by which Plasmopara viticola effectors manipulate host plant cells remain largely unclear. In this study, we reported that RXLR31154, a P. viticola RXLR effector, was highly expressed during the early stages of P. viticola infection. In our study, stable expression of RXLR31154 in grapevine (Vitis vinifera) and Nicotiana benthamiana promoted leaf colonization by P. viticola and Phytophthora capsici, respectively. By yeast two-hybrid screening, the 23-kDa oxygen-evolving enhancer 2 (VpOEE2 or VpPsbP), encoded by the PsbP gene, in Vitis piasezkii accession Liuba-8 was identified as a host target of RXLR31154. Overexpression of VpPsbP enhanced susceptibility to P. viticola in grapevine and P. capsici in N. benthamiana, and silencing of NbPsbPs, the homologs of PsbP in N. benthamiana, reduced P. capcisi colonization, indicating that PsbP is a susceptibility factor. RXLR31154 and VpPsbP protein were co-localized in the chloroplast. Moreover, VpPsbP reduced H2 O2 accumulation and activated the 1 O2 signaling pathway in grapevine. RXLR31154 could stabilize PsbP. Together, our data revealed that RXLR31154 reduces H2 O2 accumulation and activates the 1 O2 signaling pathway through stabilizing PsbP, thereby promoting disease.
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Affiliation(s)
- Ruiqi Liu
- State Key Laboratory of Crop Stress Biology in Arid Areas (Northwest A&F University), Yangling, Shaanxi, P.R. China
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P.R. China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, P.R. China
| | - Tingting Chen
- State Key Laboratory of Crop Stress Biology in Arid Areas (Northwest A&F University), Yangling, Shaanxi, P.R. China
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P.R. China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, P.R. China
| | - Xiao Yin
- State Key Laboratory of Crop Stress Biology in Arid Areas (Northwest A&F University), Yangling, Shaanxi, P.R. China
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P.R. China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, P.R. China
| | - Gaoqing Xiang
- State Key Laboratory of Crop Stress Biology in Arid Areas (Northwest A&F University), Yangling, Shaanxi, P.R. China
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P.R. China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, P.R. China
| | - Jing Peng
- State Key Laboratory of Crop Stress Biology in Arid Areas (Northwest A&F University), Yangling, Shaanxi, P.R. China
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P.R. China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, P.R. China
| | - Qingqing Fu
- State Key Laboratory of Crop Stress Biology in Arid Areas (Northwest A&F University), Yangling, Shaanxi, P.R. China
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P.R. China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, P.R. China
| | - Mengyuan Li
- State Key Laboratory of Crop Stress Biology in Arid Areas (Northwest A&F University), Yangling, Shaanxi, P.R. China
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P.R. China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, P.R. China
| | - Boxing Shang
- State Key Laboratory of Crop Stress Biology in Arid Areas (Northwest A&F University), Yangling, Shaanxi, P.R. China
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P.R. China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, P.R. China
| | - Hui Ma
- State Key Laboratory of Crop Stress Biology in Arid Areas (Northwest A&F University), Yangling, Shaanxi, P.R. China
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P.R. China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, P.R. China
| | - Guotian Liu
- State Key Laboratory of Crop Stress Biology in Arid Areas (Northwest A&F University), Yangling, Shaanxi, P.R. China
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P.R. China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, P.R. China
| | - Yuejin Wang
- State Key Laboratory of Crop Stress Biology in Arid Areas (Northwest A&F University), Yangling, Shaanxi, P.R. China
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P.R. China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, P.R. China
| | - Yan Xu
- State Key Laboratory of Crop Stress Biology in Arid Areas (Northwest A&F University), Yangling, Shaanxi, P.R. China
- College of Horticulture, Northwest A&F University, Yangling, Shaanxi, P.R. China
- Key Laboratory of Horticultural Plant Biology and Germplasm Innovation in Northwest China, Ministry of Agriculture, Yangling, Shaanxi, P.R. China
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Blifernez-Klassen O, Berger H, Mittmann BGK, Klassen V, Schelletter L, Buchholz T, Baier T, Soleimani M, Wobbe L, Kruse O. A gene regulatory network for antenna size control in carbon dioxide-deprived Chlamydomonas reinhardtii cells. THE PLANT CELL 2021; 33:1303-1318. [PMID: 33793853 DOI: 10.1093/plcell/koab012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 01/12/2021] [Indexed: 06/12/2023]
Abstract
In green microalgae, prolonged exposure to inorganic carbon depletion requires long-term acclimation responses, involving modulated gene expression and the adjustment of photosynthetic activity to the prevailing supply of carbon dioxide. Here, we describe a microalgal regulatory cycle that adjusts the light-harvesting capacity at photosystem II (PSII) to the prevailing supply of carbon dioxide in Chlamydomonas (Chlamydomonas reinhardtii). It engages low carbon dioxide response factor (LCRF), a member of the squamosa promoter-binding protein (SBP) family of transcription factors, and the previously characterized cytosolic translation repressor nucleic acid-binding protein 1 (NAB1). LCRF combines a DNA-binding SBP domain with a conserved domain for protein-protein interaction. LCRF transcription is rapidly induced by carbon dioxide depletion. LCRF activates NAB1 transcription by specifically binding to tetranucleotide motifs present in its promoter. Accumulation of the NAB1 protein enhances translational repression of its prime target mRNA, encoding the PSII-associated major light-harvesting protein LHCBM6. The resulting truncation of the PSII antenna size helps maintaining a low excitation during carbon dioxide limitation. Analyses of low carbon dioxide acclimation in nuclear insertion mutants devoid of a functional LCRF gene confirm the essentiality of this novel transcription factor for the regulatory circuit.
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Affiliation(s)
- Olga Blifernez-Klassen
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Hanna Berger
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Birgit Gerlinde Katharina Mittmann
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Viktor Klassen
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Louise Schelletter
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Tatjana Buchholz
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Thomas Baier
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Maryna Soleimani
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Lutz Wobbe
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
| | - Olaf Kruse
- Algae Biotechnology and Bioenergy, Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universit�tsstrasse 27, 33615, Bielefeld, Germany
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13
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Guardini Z, Dall’Osto L, Barera S, Jaberi M, Cazzaniga S, Vitulo N, Bassi R. High Carotenoid Mutants of Chlorella vulgaris Show Enhanced Biomass Yield under High Irradiance. PLANTS 2021; 10:plants10050911. [PMID: 34062906 PMCID: PMC8147269 DOI: 10.3390/plants10050911] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 12/30/2022]
Abstract
Microalgae represent a carbon-neutral source of bulk biomass, for extraction of high-value compounds and production of renewable fuels. Due to their high metabolic activity and reproduction rates, species of the genus Chlorella are highly productive when cultivated in photobioreactors. However, wild-type strains show biological limitations making algal bioproducts expensive compared to those extracted from other feedstocks. Such constraints include inhomogeneous light distribution due to high optical density of the culture, and photoinhibition of the surface-exposed cells. Thus, the domestication of algal strains for industry makes it increasingly important to select traits aimed at enhancing light-use efficiency while withstanding excess light stress. Carotenoids have a crucial role in protecting against photooxidative damage and, thus, represent a promising target for algal domestication. We applied chemical mutagenesis to Chlorella vulgaris and selected for enhanced tolerance to the carotenoid biosynthesis inhibitor norflurazon. The NFR (norflurazon-resistant) strains showed an increased carotenoid pool size and enhanced tolerance towards photooxidative stress. Growth under excess light revealed an improved carbon assimilation rate of NFR strains with respect to WT. We conclude that domestication of Chlorella vulgaris, by optimizing both carotenoid/chlorophyll ratio and resistance to photooxidative stress, boosted light-to-biomass conversion efficiency under high light conditions typical of photobioreactors. Comparison with strains previously reported for enhanced tolerance to singlet oxygen, reveals that ROS resistance in Chlorella is promoted by at least two independent mechanisms, only one of which is carotenoid-dependent.
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14
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Morel E, Dozois J, Slaveykova VI, Wilkinson KJ. Distinguishing the effects of Ce nanoparticles from their dissolution products: identification of transcriptomic biomarkers that are specific for ionic Ce in Chlamydomonas reinhardtii. Metallomics 2020; 13:6029132. [PMID: 33570134 DOI: 10.1093/mtomcs/mfaa005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 11/05/2020] [Accepted: 12/04/2020] [Indexed: 11/12/2022]
Abstract
Cerium (Ce) is a rare earth element that is incorporated in numerous consumer products, either in its cationic form or as engineered nanoparticles (ENPs). Given the propensity of small oxide particles to dissolve, it is unclear whether biological responses induced by ENPs will be due to the nanoparticles themselves or rather due to their dissolution. This study provides the foundation for the development of transcriptomic biomarkers that are specific for ionic Ce in the freshwater alga, Chlamydomonas reinhardtii, exposed either to ionic Ce or to two different types of small Ce ENPs (uncoated, ∼10 nm, or citrate-coated, ∼4 nm). Quantitative reverse transcription PCR was used to analyse mRNA levels of four ionic Ce-specific genes (Cre17g.737300, MMP6, GTR12, and HSP22E) that were previously identified by whole transcriptome analysis in addition to two oxidative stress biomarkers (APX1 and GPX5). Expression was characterized for exposures to 0.03-3 µM Ce, for 60-360 min and for pH 5.0-8.0. Near-linear concentration-response curves were obtained for the ionic Ce and as a function of exposure time. Some variability in the transcriptomic response was observed as a function of pH, which was attributed to the formation of metastable Ce species in solution. Oxidative stress biomarkers analysed at transcriptomic and cellular levels confirmed that different effects were induced for dissolved Ce in comparison to Ce ENPs. The measured expression levels confirmed that changes in Ce speciation and the dissolution of Ce ENPs greatly influence Ce bioavailability.
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Affiliation(s)
- Elise Morel
- Biophysical Environmental Chemistry Group, University of Montreal, PO Box 6128, Succ. Centre-Ville, Montreal, QC, Canada
| | - Jessica Dozois
- Biophysical Environmental Chemistry Group, University of Montreal, PO Box 6128, Succ. Centre-Ville, Montreal, QC, Canada
| | - Vera I Slaveykova
- Environmental Biogeochemistry and Ecotoxicology, Department F.-A. Forel for Environmental and Aquatic Sciences, School of Earth and Environmental Sciences, Faculty of Science, University of Geneva, Uni Carl Vogt, 66, boulevard Carl-Vogt, CH-1211 Genève 4, Switzerland
| | - Kevin J Wilkinson
- Biophysical Environmental Chemistry Group, University of Montreal, PO Box 6128, Succ. Centre-Ville, Montreal, QC, Canada
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15
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Glutathione peroxidase 5 deficiency induces lipid metabolism regulated by reactive oxygen species in Chlamydomonas reinhardtii. Microb Pathog 2020; 147:104358. [PMID: 32599138 DOI: 10.1016/j.micpath.2020.104358] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 06/09/2020] [Accepted: 06/19/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Reactive oxygen species (ROS) are generated incidentally during natural metabolism process of aerobic photosynthetic organisms which could be either harmful for cellular components. How ROS regulated lipid metabolism and the transcriptomes of stressed cells respond to ROS in aerobic photosynthetic organisms are unclear. Glutathione peroxidases (GPXs) detoxify hydrogen peroxide or organic hydroperoxides, which are important enzymes of the antioxidant system. So the function of GPXs matters the cellular redox state. How the lipid metabolism respond to the GPXs deficiency remains to be explored. METHODS In this study, we employed a Chlamydomonas reinhardtii gpx5 knockout mutant to examine the effects of ROS on lipid metabolism. The redox state and lipid content of the parental strain CC4348 and the gpx5 mutant were detected. Besides, the transcriptomes of CC4348 and the gpx5 mutant were sequenced before and after treatment with nitrogen-free medium to obtain genome wide respond. Then we performed the functional annotation, classification and enrichment analysis based on KEGG database for the differentially expressed genes (DEGs) before and after nitrogen deprivation of CC4348 and the gpx5 mutant. RESULTS In the CC4348 cells, the lipid accumulated accompanying with increasing ROS level after treatment with nitrogen-free media. However, in the gpx5 mutant, the ROS level is much higher than that in the parental strain CC4348, unexpectedly with reduced lipid accumulation. By comparing the transcriptomes of CC4348 and gpx5 mutant, we found that both CC4348 and gpx5 mutant cells displayed upregulation of transcripts related to protein, nucleic acid, carbon metabolism and chlorophyll biosynthesis, but more proportion of genes related to lipid metabolism were up-regulated in CC4348 than that in the gpx5 mutant. CONCLUSION In CC4348, lipid metabolism was up-regulated with increasing ROS level. But in the gpx5 mutant, Lipid accumulation was less with higher ROS level, which was due to the inhibited lipid biosynthesis. Therefore, ROS provides dual-directional regulation of lipid metabolism induced by GPX5 in Chlamydomonas.
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16
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Ma X, Zhang B, Miao R, Deng X, Duan Y, Cheng Y, Zhang W, Shi M, Huang K, Xia XQ. Transcriptomic and Physiological Responses to Oxidative Stress in a Chlamydomonas reinhardtii Glutathione Peroxidase Mutant. Genes (Basel) 2020; 11:genes11040463. [PMID: 32344528 PMCID: PMC7230881 DOI: 10.3390/genes11040463] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 04/16/2020] [Accepted: 04/21/2020] [Indexed: 11/17/2022] Open
Abstract
Aerobic photosynthetic organisms such as algae produce reactive oxygen species (ROS) as by-products of metabolism. ROS damage biomolecules such as proteins and lipids in cells, but also act as signaling molecules. The mechanisms that maintain the metabolic balance in aerobic photosynthetic organisms and how the cells specifically respond to different levels of ROS are unclear. Glutathione peroxidase (GPX) enzymes detoxify hydrogen peroxide or organic hydroperoxides, and thus are important components of the antioxidant system. In this study, we employed a Chlamydomonas reinhardtii glutathione peroxidase knockout (gpx5) mutant to identify the genetic response to singlet oxygen (1O2) generated by the photosensitizer rose bengal (RB). To this end, we compared the transcriptomes of the parental strain CC4348 and the gpx5 mutant sampled before, and 1 h after, the addition of RB. Functional annotation of differentially expressed genes showed that genes encoding proteins related to ROS detoxification, stress-response-related molecular chaperones, and ubiquitin–proteasome pathway genes were upregulated in CC4338. When GPX5 was mutated, higher oxidative stress specifically induced the TCA cycle and enhanced mitochondrial electron transport. Transcription of selenoproteins and flagellar-associated proteins was depressed in CC4348 and the gpx5 mutant. In addition, we found iron homeostasis played an important role in maintaining redox homeostasis, and we uncovered the relationship between 1O2 stress and iron assimilation, as well as selenoproteins. Based on the observed expression profiles in response to different levels of oxidative stress, we propose a model for dose-dependent responses to different ROS levels in Chlamydomonas.
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Affiliation(s)
- Xiaocui Ma
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China; (X.M.); (B.Z.); (R.M.); (X.D.); (Y.D.); (Y.C.); (W.Z.); (M.S.)
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Baolong Zhang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China; (X.M.); (B.Z.); (R.M.); (X.D.); (Y.D.); (Y.C.); (W.Z.); (M.S.)
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Rongli Miao
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China; (X.M.); (B.Z.); (R.M.); (X.D.); (Y.D.); (Y.C.); (W.Z.); (M.S.)
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Xuan Deng
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China; (X.M.); (B.Z.); (R.M.); (X.D.); (Y.D.); (Y.C.); (W.Z.); (M.S.)
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China
| | - You Duan
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China; (X.M.); (B.Z.); (R.M.); (X.D.); (Y.D.); (Y.C.); (W.Z.); (M.S.)
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Yingyin Cheng
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China; (X.M.); (B.Z.); (R.M.); (X.D.); (Y.D.); (Y.C.); (W.Z.); (M.S.)
| | - Wanting Zhang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China; (X.M.); (B.Z.); (R.M.); (X.D.); (Y.D.); (Y.C.); (W.Z.); (M.S.)
| | - Mijuan Shi
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China; (X.M.); (B.Z.); (R.M.); (X.D.); (Y.D.); (Y.C.); (W.Z.); (M.S.)
| | - Kaiyao Huang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China; (X.M.); (B.Z.); (R.M.); (X.D.); (Y.D.); (Y.C.); (W.Z.); (M.S.)
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China
- Correspondence: (K.H.); (X.-Q.X.)
| | - Xiao-Qin Xia
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China; (X.M.); (B.Z.); (R.M.); (X.D.); (Y.D.); (Y.C.); (W.Z.); (M.S.)
- University of Chinese Academy of Sciences, Beijing 100039, China
- Correspondence: (K.H.); (X.-Q.X.)
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17
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Raven JA, Beardall J, Quigg A. Light-Driven Oxygen Consumption in the Water-Water Cycles and Photorespiration, and Light Stimulated Mitochondrial Respiration. PHOTOSYNTHESIS IN ALGAE: BIOCHEMICAL AND PHYSIOLOGICAL MECHANISMS 2020. [DOI: 10.1007/978-3-030-33397-3_8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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18
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High level of reactive oxygen species inhibits triacylglycerols accumulation in Chlamydomonas reinhardtii. ALGAL RES 2019. [DOI: 10.1016/j.algal.2018.101400] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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19
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Dall’Osto L, Cazzaniga S, Guardini Z, Barera S, Benedetti M, Mannino G, Maffei ME, Bassi R. Combined resistance to oxidative stress and reduced antenna size enhance light-to-biomass conversion efficiency in Chlorella vulgaris cultures. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:221. [PMID: 31534480 PMCID: PMC6745798 DOI: 10.1186/s13068-019-1566-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 09/07/2019] [Indexed: 05/20/2023]
Abstract
BACKGROUND Microalgae are efficient producers of lipid-rich biomass, making them a key component in developing a sustainable energy source, and an alternative to fossil fuels. Chlorella species are of special interest because of their fast growth rate in photobioreactors. However, biological constraints still cast a significant gap between the high cost of biofuel and cheap oil, thus hampering perspective of producing CO2-neutral biofuels. A key issue is the inefficient use of light caused by its uneven distribution in the culture that generates photoinhibition of the surface-exposed cells and darkening of the inner layers. Efficient biofuel production, thus, requires domestication, including traits which reduce optical density of cultures and enhance photoprotection. RESULTS We applied two steps of mutagenesis and phenotypic selection to the microalga Chlorella vulgaris. First, a pale-green mutant (PG-14) was selected, with a 50% reduction of both chlorophyll content per cell and LHCII complement per PSII, with respect to WT. PG-14 showed a 30% increased photon conversion into biomass efficiency vs. WT. A second step of mutagenesis of PG-14, followed by selection for higher tolerance to Rose Bengal, led to the isolation of pale-green genotypes, exhibiting higher resistance to singlet oxygen (strains SOR). Growth in photobioreactors under high light conditions showed an enhanced biomass production of SOR strains with respect to PG-14. When compared to WT strain, biomass yield of the pale green + sor genotype was enhanced by 68%. CONCLUSIONS Domestication of microalgae like Chlorella vulgaris, by optimizing both light distribution and ROS resistance, yielded an enhanced carbon assimilation rate in photobioreactor.
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Affiliation(s)
- Luca Dall’Osto
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Stefano Cazzaniga
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Zeno Guardini
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Simone Barera
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Manuel Benedetti
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
| | - Giuseppe Mannino
- Dipartimento di Scienze della Vita e Biologia dei Sistemi, Unità di Fisiologia Vegetale, Università di Torino, Via Quarello 15/a, 10135 Turin, Italy
| | - Massimo E. Maffei
- Dipartimento di Scienze della Vita e Biologia dei Sistemi, Unità di Fisiologia Vegetale, Università di Torino, Via Quarello 15/a, 10135 Turin, Italy
| | - Roberto Bassi
- Dipartimento di Biotecnologie, Università di Verona, Strada Le Grazie 15, 37134 Verona, Italy
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20
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Roach T, Stöggl W, Baur T, Kranner I. Distress and eustress of reactive electrophiles and relevance to light stress acclimation via stimulation of thiol/disulphide-based redox defences. Free Radic Biol Med 2018; 122:65-73. [PMID: 29563047 DOI: 10.1016/j.freeradbiomed.2018.03.030] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 03/10/2018] [Accepted: 03/16/2018] [Indexed: 01/30/2023]
Abstract
Photosynthetic organisms suffering from light stress have to cope with an increased formation of reactive short-chain aldehydes. Singlet oxygen generated from highly-charged reaction centres can peroxidise the poly-unsaturated fatty acid (PUFA)-rich thylakoid membranes they are embedded in. Lipid peroxides decay to release α,β-unsaturated aldehydes that are reactive electrophile species (RES). Acrolein is one of the most abundant and reactive RES produced in chloroplasts. Here, in the model chlorophyte alga Chlamydomonas reinhardtii, a clear concentration-dependent "distress" induced by acrolein intoxication was observed in conjunction with depletion of the glutathione pool. The glutathione redox state (EGSSG/2GSH) strongly correlated (R2 = 0.95) with decreasing Fv/Fm values of chlorophyll fluorescence. However, treatment of C. reinhardtii with sub-toxic acrolein concentrations increased glutathione concentrations and raised the protein levels of a glutathione-S-transferase (GSTS1), mimicking the response to excess light, indicating that at lower concentrations, acrolein may contribute to high light acclimation, which could be interpreted as "eustress". Furthermore, similar patterns of chloroplastic protein carbonylation occurred under light stress and in response to exogenous acrolein. Priming cells by low doses of acrolein increased the alga's resistance to singlet oxygen. A RNA seq. analysis showed a large overlap in gene regulation under singlet oxygen and acrolein stresses. Particularly enriched were transcripts of enzymes involved in thiol/disulphide exchanges. Some of the genes are regulated by the SOR1 transcription factor, but acrolein treatment still induced an increase in glutathione contents and enhanced singlet oxygen tolerance of the sor1 mutant. The results support a role for RES in chloroplast-to-nucleus retrograde signalling during high light acclimation, with involvement of SOR1 and other pathways.
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Affiliation(s)
- Thomas Roach
- Department of Botany and Centre of Molecular Biosciences, Leopold-Franzens-Universität-Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria.
| | - Wolfgang Stöggl
- Department of Botany and Centre of Molecular Biosciences, Leopold-Franzens-Universität-Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria
| | - Theresa Baur
- Department of Botany and Centre of Molecular Biosciences, Leopold-Franzens-Universität-Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria
| | - Ilse Kranner
- Department of Botany and Centre of Molecular Biosciences, Leopold-Franzens-Universität-Innsbruck, Sternwartestrasse 15, 6020 Innsbruck, Austria
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21
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Rea G, Antonacci A, Lambreva MD, Mattoo AK. Features of cues and processes during chloroplast-mediated retrograde signaling in the alga Chlamydomonas. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 272:193-206. [PMID: 29807591 DOI: 10.1016/j.plantsci.2018.04.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/04/2018] [Accepted: 04/23/2018] [Indexed: 06/08/2023]
Abstract
Retrograde signaling is an intracellular communication process defined by cues generated in chloroplast and mitochondria which traverse membranes to their destination in the nucleus in order to regulate nuclear gene expression and protein synthesis. The coding and decoding of such organellar message(s) involve gene medleys and metabolic components about which more is known in higher plants than the unicellular organisms such as algae. Chlamydomonas reinhardtii is an oxygenic microalgal model for genetic and physiological studies. It harbors a single chloroplast and is amenable for generating mutants. The focus of this review is on studies that delineate retrograde signaling in Chlamydomonas vis a vis higher plants. Thus, communication networks between chloroplast and nucleus involving photosynthesis- and ROS-generated signals, functional tetrapyrrole biosynthesis intermediates, and Ca2+-signaling that modulate nuclear gene expression in this alga are discussed. Conceptually, different signaling components converge to regulate either the same or functionally-overlapping gene products.
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Affiliation(s)
- Giuseppina Rea
- Institute of Crystallography, National Research Council of Italy, Via Salaria Km 29, 3 00015 Monterotondo Scalo, Rome, Italy
| | - Amina Antonacci
- Institute of Crystallography, National Research Council of Italy, Via Salaria Km 29, 3 00015 Monterotondo Scalo, Rome, Italy
| | - Maya D Lambreva
- Institute of Crystallography, National Research Council of Italy, Via Salaria Km 29, 3 00015 Monterotondo Scalo, Rome, Italy
| | - Autar K Mattoo
- The Henry A Wallace Agricultural Research Centre, U.S. Department of Agriculture, Sustainable Agricultural Systems Laboratory, Beltsville, MD 20705, USA.
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Xing J, Liu P, Zhao L, Huang F. Deletion of CGLD1 Impairs PSII and Increases Singlet Oxygen Tolerance of Green Alga Chlamydomonas reinhardtii. FRONTIERS IN PLANT SCIENCE 2017; 8:2154. [PMID: 29326747 PMCID: PMC5736878 DOI: 10.3389/fpls.2017.02154] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 12/05/2017] [Indexed: 05/24/2023]
Abstract
The green alga Chlamydomonas reinhardtii is a key model organism for studying photosynthesis and oxidative stress in unicellular eukaryotes. Using a forward genetics approach, we have identified and characterized a mutant x32, which lacks a predicted protein named CGLD1 (Conserved in Green Lineage and Diatom 1) in GreenCut2, under normal and stress conditions. We show that loss of CGLD1 resulted in minimal photoautotrophic growth and PSII activity in the organism. We observed reduced amount of PSII complex and core subunits in the x32 mutant based on blue-native (BN)/PAGE and immunoblot analysis. Moreover, x32 exhibited increased sensitivity to high-light stress and altered tolerance to different reactive oxygenic species (ROS) stress treatments, i.e., decreased resistance to H2O2/or tert-Butyl hydroperoxide (t-BOOH) and increased tolerance to neutral red (NR) and rose bengal (RB) that induce the formation of singlet oxygen, respectively. Further analysis via quantitative real-time PCR (qRT-PCR) indicated that the increased singlet-oxygen tolerance of x32 was largely correlated with up-regulated gene expression of glutathione-S-transferases (GST). The phenotypical and physiological implications revealed from our experiments highlight the important roles of CGLD1 in maintaining structure and function of PSII as well as in protection of Chlamydomonas under photo-oxidative stress conditions.
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Affiliation(s)
- Jiale Xing
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Peng Liu
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lei Zhao
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Fang Huang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
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23
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Biochemistry and Physiology of Reactive Oxygen Species in Euglena. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 979:47-64. [PMID: 28429317 DOI: 10.1007/978-3-319-54910-1_4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Reactive oxygen species (ROS) such as superoxide and hydrogen peroxide are by-products of various metabolic processes in aerobic organisms including Euglena. Chloroplasts and mitochondria are the main sites of ROS generation by photosynthesis and respiration, respectively, through the active electron transport chain. An efficient antioxidant network is required to maintain intracellular ROS pools at optimal conditions for redox homeostasis. A comparison with the networks of plants and animals revealed that Euglena has acquired some aspects of ROS metabolic process. Euglena lacks catalase and a typical selenocysteine containing animal-type glutathione peroxidase for hydrogen peroxide scavenging, but contains enzymes involved in ascorbate-glutathione cycle solely in the cytosol. Ascorbate peroxidase in Euglena, which plays a central role in the ascorbate-glutathione cycle, forms a unique intra-molecular dimer structure that is related to the recognition of peroxides. We recently identified peroxiredoxin and NADPH-dependent thioredoxin reductase isoforms in cellular compartments including chloroplasts and mitochondria, indicating the physiological significance of the thioredoxin system in metabolism of ROS. Besides glutathione, Euglena contains the unusual thiol compound trypanothione, an unusual form of glutathione involving two molecules of glutathione joined by a spermidine linker, which has been identified in pathogenic protists such as Trypanosomatida and Schizopyrenida. Furthermore, in contrast to plants, photosynthesis by Euglena is not susceptible to hydrogen peroxide because of resistance of the Calvin cycle enzymes fructose-1,6-bisphosphatse, NADP+-glyceraldehyde-3-phosphatase, sedoheptulose-1,7-bisphosphatase, and phosphoribulokinase to hydrogen peroxide. Consequently, these characteristics of Euglena appear to exemplify a strategy for survival and adaptation to various environmental conditions during the evolutionary process of euglenoids.
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Roach T, Baur T, Stöggl W, Krieger-Liszkay A. Chlamydomonas reinhardtii responding to high light: a role for 2-propenal (acrolein). PHYSIOLOGIA PLANTARUM 2017; 161:75-87. [PMID: 28326554 DOI: 10.1111/ppl.12567] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 01/30/2017] [Accepted: 02/17/2017] [Indexed: 05/03/2023]
Abstract
High light causes photosystem II to generate singlet oxygen (1 O2 ), a reactive oxygen species (ROS) that can react with membrane lipids, releasing reactive electrophile species (RES), such as acrolein. To investigate how RES may contribute to light stress responses, Chlamydomonas reinhardtii was high light-treated in photoautotrophic and mixotrophic conditions and also in an oxygen-enriched atmosphere to elevate ROS production. The responses were compared to exogenous acrolein. Non-photochemical quenching (NPQ) was higher in photoautotrophic cells, as a consequence of a more de-epoxidized state of the xanthophyll cycle pool and more LHCSR3 protein, showing that photosynthesis was under more pressure than in mixotrophic cells. Photoautotrophic cells had lowered α-tocopherol and β-carotene contents and a higher level of protein carbonylation, indicators of elevated 1 O2 production. Levels of glutathione, glutathione peroxidase (GPX5) and glutathione-S-transferase (GST1), important antioxidants against RES, were also increased in photoautotrophic cells. In parallel to the wild-type, the LHCSR3-deficient npq4 mutant was high light-treated, which in photoautotrophic conditions exhibited particular sensitivity under elevated oxygen, the treatment that induced the highest RES levels, including acrolein. The npq4 mutant had more GPX5 and GST1 alongside higher levels of carbonylated protein and a more oxidized glutathione redox state. In wild-type cells glutathione contents doubled after 4 h treatment, either with high light under elevated oxygen or with a non-critical dose (600 ppm) of acrolein. Exogenous acrolein also increased GST1 levels, but not GPX5. Overall, RES-associated oxidative damage and glutathione metabolism are prominently associated with light stress and potentially in signaling responses of C. reinhardtii.
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Affiliation(s)
- Thomas Roach
- Institut für Botanik, Leopold-Franzens-Universität-Innsbruck, Innsbruck, Austria
| | - Theresa Baur
- Institut für Botanik, Leopold-Franzens-Universität-Innsbruck, Innsbruck, Austria
| | - Wolfgang Stöggl
- Institut für Botanik, Leopold-Franzens-Universität-Innsbruck, Innsbruck, Austria
| | - Anja Krieger-Liszkay
- Institut de Biologie Intégrative de la Cellule (I2BC), IBITECS, CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, Gif Sur Yvette, France
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25
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Pérez-Pérez ME, Mauriès A, Maes A, Tourasse NJ, Hamon M, Lemaire SD, Marchand CH. The Deep Thioredoxome in Chlamydomonas reinhardtii: New Insights into Redox Regulation. MOLECULAR PLANT 2017; 10:1107-1125. [PMID: 28739495 DOI: 10.1016/j.molp.2017.07.009] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 07/04/2017] [Accepted: 07/11/2017] [Indexed: 05/20/2023]
Abstract
Thiol-based redox post-translational modifications have emerged as important mechanisms of signaling and regulation in all organisms, and thioredoxin plays a key role by controlling the thiol-disulfide status of target proteins. Recent redox proteomic studies revealed hundreds of proteins regulated by glutathionylation and nitrosylation in the unicellular green alga Chlamydomonas reinhardtii, while much less is known about the thioredoxin interactome in this organism. By combining qualitative and quantitative proteomic analyses, we have comprehensively investigated the Chlamydomonas thioredoxome and 1188 targets have been identified. They participate in a wide range of metabolic pathways and cellular processes. This study broadens not only the redox regulation to new enzymes involved in well-known thioredoxin-regulated metabolic pathways but also sheds light on cellular processes for which data supporting redox regulation are scarce (aromatic amino acid biosynthesis, nuclear transport, etc). Moreover, we characterized 1052 thioredoxin-dependent regulatory sites and showed that these data constitute a valuable resource for future functional studies in Chlamydomonas. By comparing this thioredoxome with proteomic data for glutathionylation and nitrosylation at the protein and cysteine levels, this work confirms the existence of a complex redox regulation network in Chlamydomonas and provides evidence of a tremendous selectivity of redox post-translational modifications for specific cysteine residues.
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Affiliation(s)
- María Esther Pérez-Pérez
- Institut de Biologie Physico-Chimique, UMR8226, CNRS, Sorbonne Universités, UPMC Univ Paris 06, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Adeline Mauriès
- Institut de Biologie Physico-Chimique, UMR8226, CNRS, Sorbonne Universités, UPMC Univ Paris 06, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Alexandre Maes
- Institut de Biologie Physico-Chimique, UMR8226, CNRS, Sorbonne Universités, UPMC Univ Paris 06, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Nicolas J Tourasse
- Institut de Biologie Physico-Chimique, Plateforme de Protéomique, FRC550, CNRS, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Marion Hamon
- Institut de Biologie Physico-Chimique, UMR8226, CNRS, Sorbonne Universités, UPMC Univ Paris 06, 13 rue Pierre et Marie Curie, 75005 Paris, France; Institut de Biologie Physico-Chimique, Plateforme de Protéomique, FRC550, CNRS, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Stéphane D Lemaire
- Institut de Biologie Physico-Chimique, UMR8226, CNRS, Sorbonne Universités, UPMC Univ Paris 06, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Christophe H Marchand
- Institut de Biologie Physico-Chimique, UMR8226, CNRS, Sorbonne Universités, UPMC Univ Paris 06, 13 rue Pierre et Marie Curie, 75005 Paris, France; Institut de Biologie Physico-Chimique, Plateforme de Protéomique, FRC550, CNRS, 13 rue Pierre et Marie Curie, 75005 Paris, France.
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26
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Blaby IK, Blaby-Haas CE, Pérez-Pérez ME, Schmollinger S, Fitz-Gibbon S, Lemaire SD, Merchant SS. Genome-wide analysis on Chlamydomonas reinhardtii reveals the impact of hydrogen peroxide on protein stress responses and overlap with other stress transcriptomes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 84:974-988. [PMID: 26473430 PMCID: PMC4715741 DOI: 10.1111/tpj.13053] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 10/07/2015] [Indexed: 05/18/2023]
Abstract
Reactive oxygen species (ROS) are produced by and have the potential to be damaging to all aerobic organisms. In photosynthetic organisms, they are an unavoidable byproduct of electron transfer in both the chloroplast and mitochondrion. Here, we employ the reference unicellular green alga Chlamydomonas reinhardtii to identify the effect of H2O2 on gene expression by monitoring the changes in the transcriptome in a time-course experiment. Comparison of transcriptomes from cells sampled immediately prior to the addition of H2O2 and 0.5 and 1 h subsequently revealed 1278 differentially abundant transcripts. Of those transcripts that increase in abundance, many encode proteins involved in ROS detoxification, protein degradation and stress responses, whereas among those that decrease are transcripts encoding proteins involved in photosynthesis and central carbon metabolism. In addition to these transcriptomic adjustments, we observe that addition of H2O2 is followed by an accumulation and oxidation of the total intracellular glutathione pool, and a decrease in photosynthetic O2 output. Additionally, we analyze our transcriptomes in the context of changes in transcript abundance in response to singlet O2 (O2*), and relate our H2O2 -induced transcripts to a diurnal transcriptome, where we demonstrate enrichments of H2O2 -induced transcripts early in the light phase, late in the light phase and 2 h prior to light. On this basis several genes that are highlighted in this work may be involved in previously undiscovered stress remediation pathways or acclimation responses.
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Affiliation(s)
- Ian K Blaby
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095
| | - Crysten E Blaby-Haas
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095
| | - María Esther Pérez-Pérez
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR8226, Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Stefan Schmollinger
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095
| | - Sorel Fitz-Gibbon
- Institute for Genomics and Proteomics, University of California, Los Angeles, CA 90095
| | - Stéphane D Lemaire
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR8226, Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Sabeeha S Merchant
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095
- Institute for Genomics and Proteomics, University of California, Los Angeles, CA 90095
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27
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Korkaric M, Xiao M, Behra R, Eggen RIL. Acclimation of Chlamydomonas reinhardtii to ultraviolet radiation and its impact on chemical toxicity. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2015; 167:209-219. [PMID: 26349947 DOI: 10.1016/j.aquatox.2015.08.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 08/14/2015] [Accepted: 08/18/2015] [Indexed: 06/05/2023]
Abstract
The toxicity of chemical pollutants can be modulated under stressful environmental conditions, such as increased temperature, salinity or ultraviolet radiation (UVR), due to the interaction of effects during simultaneous stressor exposure. However, organisms may acclimate to such conditions by activation of physiological and biochemical defence mechanisms. In sequential exposures, organisms acclimated to environmental stressors may display an increased sensitivity or co-tolerance towards chemical pollutants. It has been suggested that co-tolerance might be expected for similarly acting stressors due to common defence mechanisms. To test this for combinations of UVR and chemical stressors, we first acclimatized the model green alga Chlamydomonas reinhardtii to UVR and subsequently compared the sensitivity of UVR pre-exposed and control algae towards chemicals. Selected chemicals all act on photosynthesis and thus share a common physiological target, but display distinct toxicity mechanisms. Results showed that UVR pre-exposure for four days partially inhibited algal growth and photosynthesis, but also increased algal tolerance to higher UVR levels, confirming UVR acclimation. HPLC analysis of algal pigments indicated that UVR acclimation might in part be explained by the protective function of lutein while the contribution of UVR absorbing compounds was less clear. Challenge exposure to chemicals in the absence of UVR showed that acclimated algae were co-tolerant to the photosensitizer rose bengal, but not to the herbicides paraquat and diuron, suggesting that the fast physiological and biochemical defence mechanisms that conferred tolerance of algae towards higher UVR levels were related to singlet oxygen defence. The presented study suggests that knowledge of the molecular toxicity mechanisms of chemicals, rather than their general physiological target, is needed in order to predict co-tolerance between environmental and chemical stressors.
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Affiliation(s)
- Muris Korkaric
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, 8600 Duebendorf, Switzerland; ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics, 8092 Zürich, Switzerland
| | - Mao Xiao
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, 8600 Duebendorf, Switzerland; ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics, 8092 Zürich, Switzerland
| | - Renata Behra
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, 8600 Duebendorf, Switzerland
| | - Rik I L Eggen
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, 8600 Duebendorf, Switzerland; ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics, 8092 Zürich, Switzerland.
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28
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Activation of Autophagy by Metals in Chlamydomonas reinhardtii. EUKARYOTIC CELL 2015; 14:964-73. [PMID: 26163317 DOI: 10.1128/ec.00081-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 07/05/2015] [Indexed: 12/31/2022]
Abstract
Autophagy is an intracellular self-degradation pathway by which eukaryotic cells recycle their own material in response to specific stress conditions. Exposure to high concentrations of metals causes cell damage, although the effect of metal stress on autophagy has not been explored in photosynthetic organisms. In this study, we investigated the effect of metal excess on autophagy in the model unicellular green alga Chlamydomonas reinhardtii. We show in cells treated with nickel an upregulation of ATG8 that is independent of CRR1, a global regulator of copper signaling in Chlamydomonas. A similar effect on ATG8 was observed with copper and cobalt but not with cadmium or mercury ions. Transcriptome sequencing data revealed an increase in the abundance of the protein degradation machinery, including that responsible for autophagy, and a substantial overlap of that increased abundance with the hydrogen peroxide response in cells treated with nickel ions. Thus, our results indicate that metal stress triggers autophagy in Chlamydomonas and suggest that excess nickel may cause oxidative damage, which in turn activates degradative pathways, including autophagy, to clear impaired components and recover cellular homeostasis.
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29
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Juergens MT, Deshpande RR, Lucker BF, Park JJ, Wang H, Gargouri M, Holguin FO, Disbrow B, Schaub T, Skepper JN, Kramer DM, Gang DR, Hicks LM, Shachar-Hill Y. The regulation of photosynthetic structure and function during nitrogen deprivation in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2015; 167:558-73. [PMID: 25489023 PMCID: PMC4326741 DOI: 10.1104/pp.114.250530] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 12/01/2014] [Indexed: 05/19/2023]
Abstract
The accumulation of carbon storage compounds by many unicellular algae after nutrient deprivation occurs despite declines in their photosynthetic apparatus. To understand the regulation and roles of photosynthesis during this potentially bioenergetically valuable process, we analyzed photosynthetic structure and function after nitrogen deprivation in the model alga Chlamydomonas reinhardtii. Transcriptomic, proteomic, metabolite, and lipid profiling and microscopic time course data were combined with multiple measures of photosynthetic function. Levels of transcripts and proteins of photosystems I and II and most antenna genes fell with differing trajectories; thylakoid membrane lipid levels decreased, while their proportions remained similar and thylakoid membrane organization appeared to be preserved. Cellular chlorophyll (Chl) content decreased more than 2-fold within 24 h, and we conclude from transcript protein and (13)C labeling rates that Chl synthesis was down-regulated both pre- and posttranslationally and that Chl levels fell because of a rapid cessation in synthesis and dilution by cellular growth rather than because of degradation. Photosynthetically driven oxygen production and the efficiency of photosystem II as well as P700(+) reduction and electrochromic shift kinetics all decreased over the time course, without evidence of substantial energy overflow. The results also indicate that linear electron flow fell approximately 15% more than cyclic flow over the first 24 h. Comparing Calvin-Benson cycle transcript and enzyme levels with changes in photosynthetic (13)CO2 incorporation rates also pointed to a coordinated multilevel down-regulation of photosynthetic fluxes during starch synthesis before the induction of high triacylglycerol accumulation rates.
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Affiliation(s)
- Matthew T Juergens
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Rahul R Deshpande
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Ben F Lucker
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Jeong-Jin Park
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Hongxia Wang
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Mahmoud Gargouri
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - F Omar Holguin
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Bradley Disbrow
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Tanner Schaub
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Jeremy N Skepper
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - David M Kramer
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - David R Gang
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Leslie M Hicks
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Yair Shachar-Hill
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
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Pérez-Martín M, Pérez-Pérez ME, Lemaire SD, Crespo JL. Oxidative stress contributes to autophagy induction in response to endoplasmic reticulum stress in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2014; 166:997-1008. [PMID: 25143584 PMCID: PMC4213124 DOI: 10.1104/pp.114.243659] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The accumulation of unfolded/misfolded proteins in the endoplasmic reticulum (ER) results in the activation of stress responses, such as the unfolded protein response or the catabolic process of autophagy to ultimately recover cellular homeostasis. ER stress also promotes the production of reactive oxygen species, which play an important role in autophagy regulation. However, it remains unknown whether reactive oxygen species are involved in ER stress-induced autophagy. In this study, we provide evidence connecting redox imbalance caused by ER stress and autophagy activation in the model unicellular green alga Chlamydomonas reinhardtii. Treatment of C. reinhardtii cells with the ER stressors tunicamycin or dithiothreitol resulted in up-regulation of the expression of genes encoding ER resident endoplasmic reticulum oxidoreductin1 oxidoreductase and protein disulfide isomerases. ER stress also triggered autophagy in C. reinhardtii based on the protein abundance, lipidation, cellular distribution, and mRNA levels of the autophagy marker ATG8. Moreover, increases in the oxidation of the glutathione pool and the expression of oxidative stress-related genes were detected in tunicamycin-treated cells. Our results revealed that the antioxidant glutathione partially suppressed ER stress-induced autophagy and decreased the toxicity of tunicamycin, suggesting that oxidative stress participates in the control of autophagy in response to ER stress in C. reinhardtii In close agreement, we also found that autophagy activation by tunicamycin was more pronounced in the C. reinhardtii sor1 mutant, which shows increased expression of oxidative stress-related genes.
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Affiliation(s)
- Marta Pérez-Martín
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, 41092 Seville, Spain (M.P.-M., J.L.C.); andCentre National de la Recherche Scientifique (M.E.P.-P.; S.D.L.) andSorbonne Universités, Université Pierre et Marie Curie, University of Paris 06 (M.E.P.-P.; S.D.L.), Unité Mixte de Recherche 8226, Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - María Esther Pérez-Pérez
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, 41092 Seville, Spain (M.P.-M., J.L.C.); andCentre National de la Recherche Scientifique (M.E.P.-P.; S.D.L.) andSorbonne Universités, Université Pierre et Marie Curie, University of Paris 06 (M.E.P.-P.; S.D.L.), Unité Mixte de Recherche 8226, Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Stéphane D Lemaire
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, 41092 Seville, Spain (M.P.-M., J.L.C.); andCentre National de la Recherche Scientifique (M.E.P.-P.; S.D.L.) andSorbonne Universités, Université Pierre et Marie Curie, University of Paris 06 (M.E.P.-P.; S.D.L.), Unité Mixte de Recherche 8226, Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - José L Crespo
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, 41092 Seville, Spain (M.P.-M., J.L.C.); andCentre National de la Recherche Scientifique (M.E.P.-P.; S.D.L.) andSorbonne Universités, Université Pierre et Marie Curie, University of Paris 06 (M.E.P.-P.; S.D.L.), Unité Mixte de Recherche 8226, Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Institut de Biologie Physico-Chimique, 75005 Paris, France
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31
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Brzezowski P, Schlicke H, Richter A, Dent RM, Niyogi KK, Grimm B. The GUN4 protein plays a regulatory role in tetrapyrrole biosynthesis and chloroplast-to-nucleus signalling in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 79:285-98. [PMID: 24861705 DOI: 10.1111/tpj.12560] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/02/2014] [Accepted: 05/09/2014] [Indexed: 05/08/2023]
Abstract
The GENOMES UNCOUPLED 4 (GUN4) protein is found only in aerobic photosynthetic organisms. We investigated the role of GUN4 in metabolic activities of the Mg branch of the tetrapyrrole biosynthesis pathway and the plastid signal-mediated changes of nuclear gene expression in Chlamydomonas reinhardtii. In light, gun4 accumulates only 40% of the wild-type chlorophyll level. Light- or dark-grown gun4 mutant accumulates high levels of protoporphyrin IX (Proto), and displays increased sensitivity to moderate light intensities. Despite the photooxidative stress, gun4 fails to downregulate mRNA levels of the tetrapyrrole biosynthesis and the photosynthesis-associated nuclear genes (PhANGs). In contrast, upon illumination, the Proto-accumulating and light-sensitive chlD-1 mutant displays the expected downregulation of the same nuclear genes. Although chlD-1 and the wild type have similar GUN4 transcript levels, the GUN4 protein in chlD-1 is hardly detectable. Overexpression of GUN4 in chlD-1 modifies the downregulation of nuclear gene expression, but also increases light tolerance. Therefore, GUN4 is proposed to function in 'shielding' Proto, and most likely MgProto, by reducing reactivity with O2 . Furthermore, GUN4 seems to be involved in sensing elevated levels of these photoreactive tetrapyrrole intermediates, and contributing to (1) O2 -mediated retrograde signalling, originating from chlorophyll biosynthesis.
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Affiliation(s)
- Pawel Brzezowski
- Institute of Biology/Plant Physiology, Humboldt University, Philippstraße 13, 10115, Berlin, Germany
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Fischer BB, Hideg É, Krieger-Liszkay A. Production, detection, and signaling of singlet oxygen in photosynthetic organisms. Antioxid Redox Signal 2013; 18:2145-62. [PMID: 23320833 DOI: 10.1089/ars.2012.5124] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
SIGNIFICANCE In photosynthetic organisms, excited chlorophylls (Chl) can stimulate the formation of singlet oxygen ((1)O(2)), a highly toxic molecule that acts in addition to its damaging nature as an important signaling molecule. Thus, due to this dual role of (1)O(2), its production and detoxification have to be strictly controlled. RECENT ADVANCES Regulation of pigment synthesis is essential to control (1)O(2) production, and several components of the Chl synthesis and pigment insertion machineries to assemble and disassemble protein/pigment complexes have recently been identified. Once produced, (1)O(2) activates a signaling cascade from the chloroplast to the nucleus that can involve multiple mechanisms and stimulate a specific gene expression response. Further, (1)O(2) signaling was shown to interact with signal cascades of other reactive oxygen species, oxidized carotenoids, and lipid hydroperoxide-derived reactive electrophile species. CRITICAL ISSUES Despite recent progresses, hardly anything is known about how and where the (1)O(2) signal is sensed and transmitted to the cytoplasm. One reason for that is the limitation of available detection methods challenging the reliable quantification and localization of (1)O(2) in plant cells. In addition, the process of Chl insertion into the reaction centers and antenna complexes is still unclear. FUTURE DIRECTIONS Unraveling the mechanisms controlling (1)O(2) production and signaling would help clarifying the specific role of (1)O(2) in cellular stress responses. It would further enable to investigate the interaction and sensitivity to other abiotic and biotic stress signals and thus allow to better understand why some stressors activate an acclimation, while others provoke a programmed cell death response.
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Affiliation(s)
- Beat B Fischer
- Department of Environmental Toxicology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.
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33
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Cirulis JT, Scott JA, Ross GM. Management of oxidative stress by microalgae. Can J Physiol Pharmacol 2013; 91:15-21. [PMID: 23368282 DOI: 10.1139/cjpp-2012-0249] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this review is to provide an overview of the current research on oxidative stress in eukaryotic microalgae and the antioxidant compounds microalgae utilize to control oxidative stress. With the potential to exploit microalgae for the large-scale production of antioxidants, interest in how microalgae manage oxidative stress is growing. Microalgae can experience increased levels of oxidative stress and toxicity as a result of environmental conditions, metals, and chemicals. The defence mechanisms for microalgae include antioxidant enzymes such as superoxide dismutase, catalase, peroxidases, and glutathione reductase, as well as non-enzymatic antioxidant molecules such as phytochelatins, pigments, polysaccharides, and polyphenols. Discussed herein are the 3 areas the literature has focused on, including how conditions stress microalgae and how microalgae respond to oxidative stress by managing reactive oxygen species. The third area is how beneficial microalgae antioxidants are when administered to cancerous mammalian cells or to rodents experiencing oxidative stress.
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Affiliation(s)
- Judith T Cirulis
- Medical Sciences, Northern Ontario School of Medicine, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON P3E 2C6, Canada
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Brzezowski P, Wilson KE, Gray GR. The PSBP2 protein of Chlamydomonas reinhardtii is required for singlet oxygen-dependent signaling. PLANTA 2012; 236:1289-1303. [PMID: 22718311 DOI: 10.1007/s00425-012-1683-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Accepted: 05/30/2012] [Indexed: 06/01/2023]
Abstract
In the green alga Chlamydomonas reinhardtii, the cytosolic Glutathione Peroxidase 5 gene (GPX5) is known to be transcriptionally up-regulated in response to singlet oxygen ((1)O(2)). As demonstrated by previous studies, fusion of the promoter region of GPX5 to the Arylsulfatase 2 gene (ARS2) creates an effective reporter system that can be used to monitor (1)O(2)-driven GPX5 expression. This system was also used in this study to generate a stably transformed C. reinhardtii strain which expresses ARS2 in a (1)O(2)-dependent manner, resulting in the synthesis of a functional protein with detectable activity. Using the strain of C. reinhardtii harboring a (1)O(2)-sensitive reporter construct, a secondary mutagenic screen was performed. This allowed identification of mutant cell lines that were unable to up-regulate expression of the GPX5-ARS2 fusion in response to (1)O(2). In one of these lines, the mutation was subsequently localized to the first exon of the PSBP-like gene (PSBP2). The PSBP2 gene is part of a small protein family in C. reinhardtii, also present in all angiosperms studied thus far. While each member of the PSBP protein family contains a similar domain to the PSBP1 protein, which is a member of the oxygen evolving complex of photosystem II (PSII), the PSBP2 protein does not appear to be involved in PSII function, but may function as a sensor and/or signal mediating molecule of the (1)O(2) generated in the chloroplast.
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Affiliation(s)
- Pawel Brzezowski
- Department of Biology, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada
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Ding J, Li X, Hu H. Systematic prediction of cis-regulatory elements in the Chlamydomonas reinhardtii genome using comparative genomics. PLANT PHYSIOLOGY 2012; 160:613-23. [PMID: 22915576 PMCID: PMC3461543 DOI: 10.1104/pp.112.200840] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Chlamydomonas reinhardtii is one of the most important microalgae model organisms and has been widely studied toward the understanding of chloroplast functions and various cellular processes. Further exploitation of C. reinhardtii as a model system to elucidate various molecular mechanisms and pathways requires systematic study of gene regulation. However, there is a general lack of genome-scale gene regulation study, such as global cis-regulatory element (CRE) identification, in C. reinhardtii. Recently, large-scale genomic data in microalgae species have become available, which enable the development of efficient computational methods to systematically identify CREs and characterize their roles in microalgae gene regulation. Here, we performed in silico CRE identification at the whole genome level in C. reinhardtii using a comparative genomics-based method. We predicted a large number of CREs in C. reinhardtii that are consistent with experimentally verified CREs. We also discovered that a large percentage of these CREs form combinations and have the potential to work together for coordinated gene regulation in C. reinhardtii. Multiple lines of evidence from literature, gene transcriptional profiles, and gene annotation resources support our prediction. The predicted CREs will serve, to our knowledge, as the first large-scale collection of CREs in C. reinhardtii to facilitate further experimental study of microalgae gene regulation. The accompanying software tool and the predictions in C. reinhardtii are also made available through a Web-accessible database (http://hulab.ucf.edu/research/projects/Microalgae/sdcre/motifcomb.html).
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Pérez-Pérez ME, Lemaire SD, Crespo JL. Reactive oxygen species and autophagy in plants and algae. PLANT PHYSIOLOGY 2012; 160:156-64. [PMID: 22744983 PMCID: PMC3440194 DOI: 10.1104/pp.112.199992] [Citation(s) in RCA: 152] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
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Molecular cloning and functional analyses of glutathione peroxidase homologous genes from Chlorella sp. NJ-18. Gene 2012; 501:17-23. [DOI: 10.1016/j.gene.2012.04.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2012] [Revised: 03/18/2012] [Accepted: 04/03/2012] [Indexed: 01/24/2023]
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SINGLET OXYGEN RESISTANT 1 links reactive electrophile signaling to singlet oxygen acclimation in Chlamydomonas reinhardtii. Proc Natl Acad Sci U S A 2012; 109:E1302-11. [PMID: 22529359 DOI: 10.1073/pnas.1116843109] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Acclimation of Chlamydomonas reinhardtii cells to low levels of singlet oxygen, produced either by photoreactive chemicals or high light treatment, induces a specific genetic response that strongly increases the tolerance of the algae to subsequent exposure to normally lethal singlet oxygen-producing conditions. The genetic response includes the increased expression of various oxidative stress response and detoxification genes, like the glutathione peroxidase homologous gene GPXH/GPX5 and the σ-class glutathione-S-transferase gene GSTS1. To identify components involved in the signal transduction and activation of the singlet oxygen-mediated response, a mutant selection was performed. This selection led to the isolation of the singlet oxygen resistant 1 (sor1) mutant, which is more tolerant to singlet oxygen-producing chemicals and shows a constitutively higher expression of GPXH and GSTS1. Map-based cloning revealed that the SOR1 gene encodes a basic leucine zipper transcription factor, which controls its own expression and the expression of a large number of oxidative stress response and detoxification genes. In the promoter region of many of these genes, a highly conserved 8-bp palindromic sequence element was found to be enriched. This element was essential for GSTS1 induction by increased levels of lipophilic reactive electrophile species (RES), suggesting that it functions as an electrophile response element (ERE). Furthermore, GSTS1 overexpression in sor1 requires the ERE, although it is unknown whether it occurs through direct binding of SOR1 to the ERE. RES can be formed after singlet oxygen-induced lipid peroxidation, indicating that RES-stimulated and SOR1-mediated responses of detoxification genes are part of the singlet oxygen-induced acclimation process in C. reinhardtii.
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Hydroperoxide and peroxynitrite reductase activity of poplar thioredoxin-dependent glutathione peroxidase 5: kinetics, catalytic mechanism and oxidative inactivation. Biochem J 2012; 442:369-80. [DOI: 10.1042/bj20111378] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Gpxs (glutathione peroxidases) constitute a family of peroxidases, including selenocysteine- or cysteine-containing isoforms (SeCys-Gpx or Cys-Gpx), which are regenerated by glutathione or Trxs (thioredoxins) respectively. In the present paper we show new data concerning the substrates of poplar Gpx5 and the residues involved in its catalytic mechanism. The present study establishes the capacity of this Cys-Gpx to reduce peroxynitrite with a catalytic efficiency of 106 M−1·s−1. In PtGpx5 (poplar Gpx5; Pt is Populus trichocarpa), Glu79, which replaces the glutamine residue usually found in the Gpx catalytic tetrad, is likely to be involved in substrate selectivity. Although the redox midpoint potential of the Cys44–Cys92 disulfide bond and the pKa of Cys44 are not modified in the E79Q variant, it exhibited significantly improved kinetic parameters (Kperoxide and kcat) with tert-butyl hydroperoxide. The characterization of the monomeric Y151R variant demonstrated that PtGpx5 is not an obligate homodimer. Also, we show that the conserved Phe90 is important for Trx recognition and that Trx-mediated recycling of PtGpx5 occurs via the formation of a transient disulfide bond between the Trx catalytic cysteine residue and the Gpx5 resolving cysteine residue. Finally, we demonstrate that the conformational changes observed during the transition from the reduced to the oxidized form of PtGpx5 are primarily determined by the oxidation of the peroxidatic cysteine into sulfenic acid. Also, MS analysis of in-vitro-oxidized PtGpx5 demonstrated that the peroxidatic cysteine residue can be over-oxidized into sulfinic or sulfonic acids. This suggests that some isoforms could have dual functions potentially acting as hydrogen-peroxide- and peroxynitrite-scavenging systems and/or as mediators of peroxide signalling as proposed for 2-Cys peroxiredoxins.
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Abstract
Singlet oxygen is the primary agent of photooxidative stress in microorganisms. In photosynthetic microorganisms, sensitized generation by pigments of the photosystems is the main source of singlet oxygen and, in nonphotosynthetic microorganisms, cellular cofactors such as flavins, rhodopsins, quinones, and porphyrins serve as photosensitizer. Singlet oxygen rapidly reacts with a wide range of cellular macromolecules including proteins, lipids, DNA, and RNA, and thereby further reactive substances including organic peroxides and sulfoxides are formed. Microorganisms that face high light intensities or exhibit potent photosensitizers have evolved specific mechanisms to prevent photooxidative stress. These mechanisms include the use of quenchers, such as carotenoids, which interact either with excited photosensitizer molecules or singlet oxygen itself to prevent damage of cellular molecules. Scavengers like glutathione react with singlet oxygen. Despite those protection mechanisms, damage by reactions with singlet oxygen on cellular macromolecules disturbs cellular functions. Microorganisms that regularly face photooxidative stress have evolved specific systems to sense singlet oxygen and tightly control the removal of singlet oxygen reaction products. Responses to photooxidative stress have been investigated in a range of photosynthetic and nonphotosynthetic microorganisms. However, detailed knowledge on the regulation of this response has only been obtained for the phototrophic alpha-proteobacterium Rhodobacter sphaeroides. In this organism and in related proteobacteria, the extracytoplasmic function (ECF) sigma factor RpoE is released from the cognate antisigma factor ChrR in the presence of singlet oxygen and triggers the expression of genes providing protection against photooxidative stress. Recent experiments show that singlet oxygen acts as a signal, which is sensed by yet unknown components and leads to proteolysis of ChrR. RpoE induces expression of a second alternative sigma factor, RpoH(II), which controls a large set of genes that partially overlaps with the heat-shock response controlled by RpoH(I). In addition to the transcriptional control of gene regulation by alternative sigma factors, a set of noncoding small RNAs (sRNAs) appear to affect the synthesis of several proteins involved in the response to photooxidative stress. The interaction of mRNA targets with those sRNAs is usually mediated by the RNA chaperone Hfq. Deletion of the gene encoding Hfq leads to a singlet oxygen-sensitive phenotype, which underlines the control of gene regulation on the posttranscriptional level by sRNAs in R. sphaeroides. Hence, a complex network of different regulatory components controls the defense against photooxidative stress in anoxygenic photosynthetic bacteria.
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Affiliation(s)
- J Glaeser
- Institut für Mikrobiologie und Molekularbiologie, Justus-Liebig-Universität Giessen, Giessen, Germany
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41
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Fischer BB, Eggen RIL, Niyogi KK. Characterization of singlet oxygen-accumulating mutants isolated in a screen for altered oxidative stress response in Chlamydomonas reinhardtii. BMC PLANT BIOLOGY 2010; 10:279. [PMID: 21167020 PMCID: PMC3022906 DOI: 10.1186/1471-2229-10-279] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Accepted: 12/17/2010] [Indexed: 05/03/2023]
Abstract
BACKGROUND When photosynthetic organisms are exposed to harsh environmental conditions such as high light intensities or cold stress, the production of reactive oxygen species like singlet oxygen is stimulated in the chloroplast. In Chlamydomonas reinhardtii singlet oxygen was shown to act as a specific signal inducing the expression of the nuclear glutathione peroxidase gene GPXH/GPX5 during high light stress, but little is known about the cellular mechanisms involved in this response. To investigate components affecting singlet oxygen signaling in C. reinhardtii, a mutant screen was performed. RESULTS Mutants with altered GPXH response were isolated from UV-mutagenized cells containing a GPXH-arylsulfatase reporter gene construct. Out of 5500 clones tested, no mutant deficient in GPXH induction was isolated, whereas several clones showed constitutive high GPXH expression under normal light conditions. Many of these GPXH overexpressor (gox) mutants exhibited higher resistance to oxidative stress conditions whereas others were sensitive to high light intensities. Interestingly, most gox mutants produced increased singlet oxygen levels correlating with high GPXH expression. Furthermore, different patterns of altered photoprotective parameters like non-photochemical quenching, carotenoid contents and α-tocopherol levels were detected in the various gox mutants. CONCLUSIONS Screening for mutants with altered GPXH expression resulted in the isolation of many gox mutants with increased singlet oxygen production, showing the relevance of controlling the production of this ROS in photosynthetic organisms. Phenotypic characterization of these gox mutants indicated that the mutations might lead to either stimulated triplet chlorophyll and singlet oxygen formation or reduced detoxification of singlet oxygen in the chloroplast. Furthermore, changes in multiple protection mechanisms might be responsible for high singlet oxygen formation and GPXH expression, which could either result from mutations in multiple loci or in a single gene encoding for a global regulator of cellular photoprotection mechanisms.
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Affiliation(s)
- Beat B Fischer
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102 USA
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, Ueberlandstrasse 133, CH-8600 Dübendorf, Switzerland
| | - Rik IL Eggen
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, Ueberlandstrasse 133, CH-8600 Dübendorf, Switzerland
| | - Krishna K Niyogi
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102 USA
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