1
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Imamura S, Yamada K, Takebe H, Kiuchi R, Iwashita H, Toyokawa C, Suzuki K, Sakurai A, Takaya K. Optimal conditions of algal breeding using neutral beam and applying it to breed Euglena gracilis strains with improved lipid accumulation. Sci Rep 2024; 14:14716. [PMID: 38961078 PMCID: PMC11222385 DOI: 10.1038/s41598-024-65175-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 06/18/2024] [Indexed: 07/05/2024] Open
Abstract
Microalgae are considered to be more useful and effective to use in biomass production than other photosynthesis organisms. However, microalgae need to be altered to acquire more desirable traits for the relevant purpose. Although neutron radiation is known to induce DNA mutations, there have been few studies on its application to microalgae, and the optimal relationship between irradiation intensity and mutation occurrence has not been established. In this study, using the unicellular red alga Cyanidioschyzon merolae as a model, we analyzed the relationship between the absorbed dose of two types of neutrons, high-energy (above 1 MeV) and thermal (around 25 meV) neutrons, and mutation occurrence while monitoring mutations in URA5.3 gene encoding UMP synthase. As a result, the highest mutational occurrence was observed when the cells were irradiated with 20 Gy of high-energy neutrons and 13 Gy of thermal neutrons. Using these optimal neutron irradiation conditions, we next attempted to improve the lipid accumulation of Euglena gracilis, which is a candidate strain for biofuel feedstock production. As a result, we obtained several strains with a maximum 1.3-fold increase in lipid accumulation compared with the wild-type. These results indicate that microalgae breeding by neutron irradiation is effective.
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Affiliation(s)
- Sousuke Imamura
- Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation, Musashino-shi, 180-8585, Japan.
| | - Koji Yamada
- Advanced Science Research Institute, Euglena Co., Ltd., Yokohama-shi, 230-0045, Japan
| | - Hiroaki Takebe
- Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation, Musashino-shi, 180-8585, Japan
| | - Ryu Kiuchi
- Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation, Musashino-shi, 180-8585, Japan
| | - Hidenori Iwashita
- Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation, Musashino-shi, 180-8585, Japan
| | - Chihana Toyokawa
- Advanced Science Research Institute, Euglena Co., Ltd., Yokohama-shi, 230-0045, Japan
| | - Kengo Suzuki
- Advanced Science Research Institute, Euglena Co., Ltd., Yokohama-shi, 230-0045, Japan
| | - Atsushi Sakurai
- Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation, Musashino-shi, 180-8585, Japan
| | - Kazuhiro Takaya
- Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation, Musashino-shi, 180-8585, Japan
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2
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D’Alessandro S, Velay F, Lebrun R, Zafirov D, Mehrez M, Romand S, Saadouni R, Forzani C, Citerne S, Montané MH, Robaglia C, Menand B, Meyer C, Field B. Posttranslational regulation of photosynthetic activity via the TOR kinase in plants. SCIENCE ADVANCES 2024; 10:eadj3268. [PMID: 38896607 PMCID: PMC11186500 DOI: 10.1126/sciadv.adj3268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 05/13/2024] [Indexed: 06/21/2024]
Abstract
Chloroplasts are the powerhouse of the plant cell, and their activity must be matched to plant growth to avoid photooxidative damage. We have identified a posttranslational mechanism linking the eukaryotic target of rapamycin (TOR) kinase that promotes growth and the guanosine tetraphosphate (ppGpp) signaling pathway of prokaryotic origins that regulates chloroplast activity and photosynthesis in particular. We find that RelA SpoT homolog 3 (RSH3), a nuclear-encoded enzyme responsible for ppGpp biosynthesis, interacts directly with the TOR complex via a plant-specific amino-terminal region which is phosphorylated in a TOR-dependent manner. Down-regulating TOR activity causes a rapid increase in ppGpp synthesis in RSH3 overexpressors and reduces photosynthetic capacity in an RSH-dependent manner in wild-type plants. The TOR-RSH3 signaling axis therefore regulates the equilibrium between chloroplast activity and plant growth, setting a precedent for the regulation of organellar function by TOR.
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Affiliation(s)
- Stefano D’Alessandro
- Aix Marseille Univ, CEA, CNRS, BIAM, LGBP Team, 13009 Marseille, France
- Università di Torino, Dipartimento di Scienze della vita e Biologia dei Sistemi, 10135 Torino, Italy
| | - Florent Velay
- Aix Marseille Univ, CEA, CNRS, BIAM, LGBP Team, 13009 Marseille, France
| | - Régine Lebrun
- Aix Marseille Univ, CNRS, Plate-forme Protéomique, Marseille Protéomique (MaP), IMM FR 3479, 31 Chemin Joseph Aiguier, 13009 Marseille, France
| | - Delyan Zafirov
- Aix Marseille Univ, CEA, CNRS, BIAM, LGBP Team, 13009 Marseille, France
| | - Marwa Mehrez
- Aix Marseille Univ, CEA, CNRS, BIAM, LGBP Team, 13009 Marseille, France
- Faculty of Sciences of Tunis, University of Tunis El Manar, 2092 Tunis, Tunisia
| | - Shanna Romand
- Aix Marseille Univ, CEA, CNRS, BIAM, LGBP Team, 13009 Marseille, France
| | - Rim Saadouni
- Aix Marseille Univ, CEA, CNRS, BIAM, LGBP Team, 13009 Marseille, France
- Aix Marseille Univ, CNRS, Plate-forme Protéomique, Marseille Protéomique (MaP), IMM FR 3479, 31 Chemin Joseph Aiguier, 13009 Marseille, France
| | - Céline Forzani
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France
| | - Sylvie Citerne
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France
| | | | | | - Benoît Menand
- Aix Marseille Univ, CEA, CNRS, BIAM, LGBP Team, 13009 Marseille, France
| | - Christian Meyer
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, CNRS, Université Paris-Saclay, 78000 Versailles, France
| | - Ben Field
- Aix Marseille Univ, CEA, CNRS, BIAM, LGBP Team, 13009 Marseille, France
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3
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Inazu M, Nemoto T, Omata Y, Suzuki S, Ono S, Kanno Y, Seo M, Oikawa A, Masuda S. Complete Loss of RelA and SpoT Homologs in Arabidopsis Reveals the Importance of the Plastidial Stringent Response in the Interplay between Chloroplast Metabolism and Plant Defense Response. PLANT & CELL PHYSIOLOGY 2024; 65:631-643. [PMID: 37925598 DOI: 10.1093/pcp/pcad136] [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: 06/20/2022] [Revised: 10/23/2023] [Accepted: 10/30/2023] [Indexed: 11/06/2023]
Abstract
The highly phosphorylated nucleotide, guanosine tetraphosphate (ppGpp), functions as a secondary messenger in bacteria and chloroplasts. The accumulation of ppGpp alters plastidial gene expression and metabolism, which are required for proper photosynthetic regulation and robust plant growth. However, because four plastid-localized ppGpp synthases/hydrolases function redundantly, the impact of the loss of ppGpp-dependent stringent response on plant physiology remains unclear. We used CRISPR/Cas9 technology to generate an Arabidopsis thaliana mutant lacking all four ppGpp synthases/hydrolases and characterized its phenotype. The mutant showed over 20-fold less ppGpp levels than the wild type under normal growth conditions and exhibited leaf chlorosis and increased expression of defense-related genes as well as salicylic acid and jasmonate levels upon transition to nitrogen-starvation conditions. These results demonstrate that proper levels of ppGpp in plastids are required for controlling not only plastid metabolism but also phytohormone signaling, which is essential for plant defense.
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Affiliation(s)
- Masataka Inazu
- Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Takanari Nemoto
- Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Yuto Omata
- Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Sae Suzuki
- Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Sumire Ono
- Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
| | - Yuri Kanno
- RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045 Japan
| | - Mitsunori Seo
- RIKEN Center for Sustainable Resource Science, Yokohama, 230-0045 Japan
| | - Akira Oikawa
- Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502 Japan
| | - Shinji Masuda
- Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
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4
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Turkan S, Kulasek M, Zienkiewicz A, Mierek-Adamska A, Skrzypek E, Warchoł M, Szydłowska-Czerniak A, Bartoli J, Field B, Dąbrowska GB. Guanosine tetraphosphate (ppGpp) is a new player in Brassica napus L. seed development. Food Chem 2024; 436:137648. [PMID: 37852071 DOI: 10.1016/j.foodchem.2023.137648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/23/2023] [Accepted: 09/30/2023] [Indexed: 10/20/2023]
Abstract
Rapeseed oil, constituting 12% of global vegetable oil production, is susceptible to quality degradation due to stress-induced incomplete seed degreening, fatty acid oxidation, or poor nutrient accumulation. We hypothesise that the hyperphosphorylated nucleotide alarmone ppGpp (guanosine tetraphosphate), acts as a pivotal regulator of these processes, given its established roles in nutrient management, degreening, and ROS regulation in leaves. Using qPCR, UHPLC-MS/MS, and biochemical methods, our study delves into the impact of ppGpp on seed nutritional value. We observed a positive correlation between ppGpp levels and desiccation, and a negative correlation with photosynthetic pigment levels. Trends in antioxidant activity suggest that ppGpp may negatively influence peroxidases, which are safeguarding against chlorophyll decomposition. Notably, despite increasing ppGpp levels, sugars, proteins and oils appear unaffected. This newfound role of ppGpp in seed development suggests it regulates the endogenous antioxidant system during degreening and desiccation, preserving nutritional quality. Further validation through mutant-based research is needed.
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Affiliation(s)
- Sena Turkan
- Department of Genetics, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland; Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4, 87-100 Toruń, Poland.
| | - Milena Kulasek
- Department of Genetics, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland; Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4, 87-100 Toruń, Poland.
| | - Agnieszka Zienkiewicz
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4, 87-100 Toruń, Poland.
| | - Agnieszka Mierek-Adamska
- Department of Genetics, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland; Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University in Toruń, Wileńska 4, 87-100 Toruń, Poland.
| | - Edyta Skrzypek
- Department of Biotechnology, The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland.
| | - Marzena Warchoł
- Department of Biotechnology, The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239 Kraków, Poland.
| | - Aleksandra Szydłowska-Czerniak
- Department of Analytical Chemistry and Applied Spectroscopy, Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7, 87-100 Toruń, Poland.
| | - Julia Bartoli
- Aix Marseille Univ, CNRS, LISM, UMR7255, IMM FR 3479, 31 Chemin Joseph Aiguier, 13009 Marseille, France.
| | - Ben Field
- Aix-Marseille Univ, CEA, CNRS, BIAM, UMR7265, 13009 Marseille, France.
| | - Grażyna B Dąbrowska
- Department of Genetics, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, 87-100 Toruń, Poland.
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5
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Perdoux R, Barrada A, Boulaiz M, Garau C, Belbachir C, Lecampion C, Montané MH, Menand B. A drug-resistant mutation in plant target of rapamycin validates the specificity of ATP-competitive TOR inhibitors in vivo. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 117:1344-1355. [PMID: 38011587 DOI: 10.1111/tpj.16564] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 10/27/2023] [Accepted: 11/13/2023] [Indexed: 11/29/2023]
Abstract
Kinases are major components of cellular signaling pathways, regulating key cellular activities through phosphorylation. Kinase inhibitors are efficient tools for studying kinase targets and functions, however assessing their kinase specificity in vivo is essential. The identification of resistant kinase mutants has been proposed to be the most convincing approach to achieve this goal. Here, we address this issue in plants via a pharmacogenetic screen for mutants resistant to the ATP-competitive TOR inhibitor AZD-8055. The eukaryotic TOR (Target of Rapamycin) kinase is emerging as a major hub controlling growth responses in plants largely thanks to the use of ATP-competitive inhibitors. We identified a dominant mutation in the DFG motif of the Arabidopsis TOR kinase domain that leads to very strong resistance to AZD-8055. This resistance was characterized by measuring root growth, photosystem II (PSII) activity in leaves and phosphorylation of YAK1 (Yet Another Kinase 1) and RPS6 (Ribosomal protein S6), a direct and an indirect target of TOR respectively. Using other ATP-competitive TOR inhibitors, we also show that the dominant mutation is particularly efficient for resistance to drugs structurally related to AZD-8055. Altogether, this proof-of-concept study demonstrates that a pharmacogenetic screen in Arabidopsis can be used to successfully identify the target of a kinase inhibitor in vivo and therefore to demonstrate inhibitor specificity. Thanks to the conservation of kinase families in eukaryotes, and the possibility of creating amino acid substitutions by genome editing, this work has great potential for extending studies on the evolution of signaling pathways in eukaryotes.
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Affiliation(s)
- Romain Perdoux
- Aix-Marseille Univ, CEA, CNRS, BIAM, LGBP Team, Marseille, France
| | - Adam Barrada
- Aix-Marseille Univ, CEA, CNRS, BIAM, LGBP Team, Marseille, France
| | - Manal Boulaiz
- Aix-Marseille Univ, CEA, CNRS, BIAM, LGBP Team, Marseille, France
| | - Camille Garau
- Aix-Marseille Univ, CEA, CNRS, BIAM, LGBP Team, Marseille, France
| | | | - Cécile Lecampion
- Aix-Marseille Univ, CEA, CNRS, BIAM, LGBP Team, Marseille, France
| | | | - Benoît Menand
- Aix-Marseille Univ, CEA, CNRS, BIAM, LGBP Team, Marseille, France
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6
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Zhou Y, Li X, Chen J, Li W, Wang F. Carbon sequestration performance, enzyme and photosynthetic activity, and transcriptome analysis of algae-bacteria symbiotic system after antibiotic exposure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 902:166486. [PMID: 37611703 DOI: 10.1016/j.scitotenv.2023.166486] [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: 07/11/2023] [Revised: 08/17/2023] [Accepted: 08/20/2023] [Indexed: 08/25/2023]
Abstract
Wastewater treatment technology based on algae-bacteria successfully combines pollutant purification, CO2 reduction and clean energy production to provide new insights into climate solutions. In this study, the reciprocal mechanisms between algae and bacteria were explored through physiological and biochemical levels of algae cells and differentially expressed genes (DEGs) based on the performance of immobilized algae-bacteria symbiotic particles (ABSPs) for CO2 fixation. The results showed that ABSPs promoted the CO2 fixation capacity of microalgae. The enhanced growth capacity and photosynthetic activity of algal cells in ABSPs are key to promoting CO2 uptake, and the stimulation of photosynthetic system and the promotion of Calvin cycle were the main contributors to enhanced carbon sequestration. These findings will provide guidance for carbon reduction using immobilized ABSS as well as deciphering the algae-bacteria reciprocal mechanism.
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Affiliation(s)
- Yuhang Zhou
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China
| | - Xinjie Li
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China
| | - Jiaqi Chen
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China
| | - Wenbing Li
- School of Engineering, Hangzhou Normal University, Hangzhou 311121, China.
| | - Fan Wang
- School of Engineering, Hangzhou Normal University, Hangzhou 311121, China.
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7
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Kobayashi Y, Komatsuya K, Imamura S, Nozaki T, Watanabe YI, Sato S, Dodd AN, Kita K, Tanaka K. Coordination of apicoplast transcription in a malaria parasite by internal and host cues. Proc Natl Acad Sci U S A 2023; 120:e2214765120. [PMID: 37406097 PMCID: PMC10334805 DOI: 10.1073/pnas.2214765120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 05/25/2023] [Indexed: 07/07/2023] Open
Abstract
The malaria parasite Plasmodium falciparum has a nonphotosynthetic plastid called the apicoplast, which contains its own genome. Regulatory mechanisms for apicoplast gene expression remain poorly understood, despite this organelle being crucial for the parasite life cycle. Here, we identify a nuclear-encoded apicoplast RNA polymerase σ subunit (sigma factor) which, along with the α subunit, appears to mediate apicoplast transcript accumulation. This has a periodicity reminiscent of parasite circadian or developmental control. Expression of the apicoplast subunit gene, apSig, together with apicoplast transcripts, increased in the presence of the blood circadian signaling hormone melatonin. Our data suggest that the host circadian rhythm is integrated with intrinsic parasite cues to coordinate apicoplast genome transcription. This evolutionarily conserved regulatory system might be a future target for malaria treatment.
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Affiliation(s)
- Yuki Kobayashi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama226-8503, Japan
| | - Keisuke Komatsuya
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo113-0033, Japan
- Laboratory of Biomembrane, Tokyo Metropolitan Institute of Medical Science, Tokyo156-8506, Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama226-8503, Japan
- Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation, Tokyo180-8585, Japan
| | - Tomoyoshi Nozaki
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo113-0033, Japan
| | - Yoh-ichi Watanabe
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo113-0033, Japan
| | - Shigeharu Sato
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama226-8503, Japan
- Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah88400, Malaysia
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah88400, Malaysia
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki852-8523, Japan
| | - Antony N. Dodd
- Department of Cell and Developmental Biology, John Innes Centre, NorwichNR4 7RU, United Kingdom
| | - Kiyoshi Kita
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo113-0033, Japan
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki852-8523, Japan
- Department of Host-Defense Biochemistry, Institute of Tropical Medicine, Nagasaki University, Nagasaki852-8523, Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama226-8503, Japan
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8
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Mehrez M, Romand S, Field B. New perspectives on the molecular mechanisms of stress signalling by the nucleotide guanosine tetraphosphate (ppGpp), an emerging regulator of photosynthesis in plants and algae. THE NEW PHYTOLOGIST 2023; 237:1086-1099. [PMID: 36349398 PMCID: PMC10107265 DOI: 10.1111/nph.18604] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
The nucleotides guanosine tetraphosphate and guanosine pentaphosphate (together (p)ppGpp) are found in a wide range of prokaryotic and eukaryotic organisms where they are associated with stress signalling. In this review, we will discuss recent research highlighting the role of (p)ppGpp signalling as a conserved regulator of photosynthetic activity in the chloroplasts of plants and algae, and the latest discoveries that open up new perspectives on the emerging roles of (p)ppGpp in acclimation to environmental stress. We explore how rapid advances in the study of (p)ppGpp signalling in prokaryotes are now revealing large gaps in our understanding of the molecular mechanisms of signalling by (p)ppGpp and related nucleotides in plants and algae. Filling in these gaps is likely to lead to the discovery of conserved as well as new plant- and algal-specific (p)ppGpp signalling mechanisms that will offer new insights into the taming of the chloroplast and the regulation of stress tolerance.
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Affiliation(s)
- Marwa Mehrez
- Aix‐Marseille University, CEA, CNRS, BIAM, UMR726513009MarseilleFrance
- Faculty of Sciences of Tunis, Laboratory of Molecular Genetics, Immunology and BiotechnologyUniversity of Tunis El Manar2092TunisTunisia
| | - Shanna Romand
- Aix‐Marseille University, CEA, CNRS, BIAM, UMR726513009MarseilleFrance
| | - Ben Field
- Aix‐Marseille University, CEA, CNRS, BIAM, UMR726513009MarseilleFrance
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9
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Mallén-Ponce MJ, Pérez-Pérez ME, Crespo JL. Deciphering the function and evolution of the target of rapamycin signaling pathway in microalgae. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:6993-7005. [PMID: 35710309 PMCID: PMC9664231 DOI: 10.1093/jxb/erac264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 06/16/2022] [Indexed: 06/15/2023]
Abstract
Microalgae constitute a highly diverse group of photosynthetic microorganisms that are widely distributed on Earth. The rich diversity of microalgae arose from endosymbiotic events that took place early in the evolution of eukaryotes and gave rise to multiple lineages including green algae, the ancestors of land plants. In addition to their fundamental role as the primary source of marine and freshwater food chains, microalgae are essential producers of oxygen on the planet and a major biotechnological target for sustainable biofuel production and CO2 mitigation. Microalgae integrate light and nutrient signals to regulate cell growth. Recent studies identified the target of rapamycin (TOR) kinase as a central regulator of cell growth and a nutrient sensor in microalgae. TOR promotes protein synthesis and regulates processes that are induced under nutrient stress such as autophagy and the accumulation of triacylglycerol and starch. A detailed analysis of representative genomes from the entire microalgal lineage revealed that the highly conserved central components of the TOR pathway are likely to have been present in the last eukaryotic common ancestor, and the loss of specific TOR signaling elements at an early stage in the evolution of microalgae. Here we examine the evolutionary conservation of TOR signaling components in diverse microalgae and discuss recent progress of this signaling pathway in these organisms.
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Affiliation(s)
- Manuel J Mallén-Ponce
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, Sevilla, Spain
| | - María Esther Pérez-Pérez
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, Sevilla, Spain
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10
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Henriques R, Calderan-Rodrigues MJ, Luis Crespo J, Baena-González E, Caldana C. Growing of the TOR world. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:6987-6992. [PMID: 36377640 PMCID: PMC9664224 DOI: 10.1093/jxb/erac401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Indexed: 06/16/2023]
Affiliation(s)
| | | | - José Luis Crespo
- Instituto de Bioquimica Vegetal y Fotosintesis, Consejo Superior de Investigaciones Cientificas (CSIC)-Universidad de Sevilla, Sevilla, Spain
| | - Elena Baena-González
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal and GREEN-IT Bioresources for Sustainability, ITQB-NOVA, 2780-157 Oeiras, Portugal
| | - Camila Caldana
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
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11
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Antoszewski M, Mierek-Adamska A, Dąbrowska GB. The Importance of Microorganisms for Sustainable Agriculture-A Review. Metabolites 2022; 12:1100. [PMID: 36422239 PMCID: PMC9694901 DOI: 10.3390/metabo12111100] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/04/2022] [Accepted: 11/08/2022] [Indexed: 08/27/2023] Open
Abstract
In the face of climate change, progressive degradation of the environment, including agricultural land negatively affecting plant growth and development, endangers plant productivity. Seeking efficient and sustainable agricultural techniques to replace agricultural chemicals is one of the most important challenges nowadays. The use of plant growth-promoting microorganisms is among the most promising approaches; however, molecular mechanisms underneath plant-microbe interactions are still poorly understood. In this review, we summarized the knowledge on plant-microbe interactions, highlighting the role of microbial and plant proteins and metabolites in the formation of symbiotic relationships. This review covers rhizosphere and phyllosphere microbiomes, the role of root exudates in plant-microorganism interactions, the functioning of the plant's immune system during the plant-microorganism interactions. We also emphasized the possible role of the stringent response and the evolutionarily conserved mechanism during the established interaction between plants and microorganisms. As a case study, we discussed fungi belonging to the genus Trichoderma. Our review aims to summarize the existing knowledge about plant-microorganism interactions and to highlight molecular pathways that need further investigation.
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Affiliation(s)
| | - Agnieszka Mierek-Adamska
- Department of Genetics, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Lwowska 1, 87-100 Toruń, Poland
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12
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Romand S, Abdelkefi H, Lecampion C, Belaroussi M, Dussenne M, Ksas B, Citerne S, Caius J, D'Alessandro S, Fakhfakh H, Caffarri S, Havaux M, Field B. A guanosine tetraphosphate (ppGpp) mediated brake on photosynthesis is required for acclimation to nitrogen limitation in Arabidopsis. eLife 2022; 11:75041. [PMID: 35156611 PMCID: PMC8887892 DOI: 10.7554/elife.75041] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 02/14/2022] [Indexed: 11/13/2022] Open
Abstract
Guanosine pentaphosphate and tetraphosphate (together referred to as ppGpp) are hyperphosphorylated nucleotides found in bacteria and the chloroplasts of plants and algae. In plants and algae artificial ppGpp accumulation can inhibit chloroplast gene expression, and influence photosynthesis, nutrient remobilisation, growth, and immunity. However, it is so far unknown whether ppGpp is required for abiotic stress acclimation in plants. Here, we demonstrate that ppGpp biosynthesis is necessary for acclimation to nitrogen starvation in Arabidopsis. We show that ppGpp is required for remodeling the photosynthetic electron transport chain to downregulate photosynthetic activity and for protection against oxidative stress. Furthermore, we demonstrate that ppGpp is required for coupling chloroplastic and nuclear gene expression during nitrogen starvation. Altogether, our work indicates that ppGpp is a pivotal regulator of chloroplast activity for stress acclimation in plants.
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Affiliation(s)
- Shanna Romand
- LGBP Team, Aix-Marseille University, CEA, CNRS, BIAM, Marseille, France
| | - Hela Abdelkefi
- LGBP Team, Aix-Marseille University, CEA, CNRS, BIAM, Marseille, France
| | - Cécile Lecampion
- LGBP Team, Aix-Marseille University, CEA, CNRS, BIAM, Marseille, France
| | | | - Melanie Dussenne
- LGBP Team, Aix-Marseille University, CEA, CNRS, BIAM, Marseille, France
| | - Brigitte Ksas
- Faculty of Sciences, University of Carthage, Bizerte, Tunisia
| | - Sylvie Citerne
- Institut JeanPierre Bourgin, Université Paris-Saclay, UMR1318, INRAE, Versailles, France
| | - Jose Caius
- Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris-Saclay, CNRS, INRAE, Orsay, France
| | | | - Hatem Fakhfakh
- Laboratory of Molecular Genetics, Immunology and Biotechnology, University of Tunis El Manar, Tunis, Tunisia
| | - Stefano Caffarri
- LGBP Team, Aix-Marseille University, CEA, CNRS, BIAM, Marseille, France
| | - Michel Havaux
- SAVE Team, Aix-Marseille University, CEA, CNRS, BIAM, Saint-Paul-lez-Durance,, France
| | - Benjamin Field
- LGBP Team, Aix-Marseille University, CEA, CNRS, BIAM, Marseille, France
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13
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Jin H, Lao YM, Zhou J, Cai ZH. Identification of a RelA/SpoT Homolog and Its Possible Role in the Accumulation of Astaxanthin in Haematococcus pluvialis. FRONTIERS IN PLANT SCIENCE 2022; 13:796997. [PMID: 35222463 PMCID: PMC8863741 DOI: 10.3389/fpls.2022.796997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
A RelA/SpoT homolog, HpRSH, was identified in Haematococcus pluvialis. HpRSH was found to catalyze Mg2+-dependent guanosine tetraphosphate (ppGpp) synthesis and Mn2+-dependent ppGpp hydrolysis, respectively. The transcription of HpRSH was significantly upregulated by environmental stresses, such as darkness, high light, nitrogen limitation, and salinity stress. The intracellular ppGpp level was also increased when exposed to these stresses. In addition, the classical initiator of stringent response, serine hydroxamate (SHX), was found to upregulate the transcription of HpRSH and increase the level of ppGpp. Moreover, stringent response induced by SHX or environmental stresses was proven to induce the accumulation of astaxanthin. These results indicated that stringent response regulatory system involved in the regulation of astaxanthin biosynthesis in H. pluvialis. Furthermore, stringent response was unable to induce astaxanthin accumulation under dark condition. This result implied that stringent response may regulate astaxanthin biosynthesis in a light-dependent manner.
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Affiliation(s)
- Hui Jin
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Institute for Ocean Engineering, Tsinghua University, Shenzhen, China
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yong Min Lao
- Institute for Advanced Study, Shenzhen University, Shenzhen, China
| | - Jin Zhou
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Institute for Ocean Engineering, Tsinghua University, Shenzhen, China
| | - Zhong Hua Cai
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Shenzhen International Graduate School, Institute for Ocean Engineering, Tsinghua University, Shenzhen, China
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14
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Song Y, Alyafei MS, Masmoudi K, Jaleel A, Ren M. Contributions of TOR Signaling on Photosynthesis. Int J Mol Sci 2021; 22:ijms22168959. [PMID: 34445664 PMCID: PMC8396432 DOI: 10.3390/ijms22168959] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/22/2021] [Accepted: 07/29/2021] [Indexed: 12/15/2022] Open
Abstract
The target of rapamycin (TOR) protein kinase is an atypical Ser/Thr protein kinase and evolutionally conserved among yeasts, plants, and mammals. TOR has been established as a central hub for integrating nutrient, energy, hormone, and environmental signals in all the eukaryotes. Despite the conserved functions across eukaryotes, recent research has shed light on the multifaceted roles of TOR signaling in plant-specific functional and mechanistic features. One of the most specific features is the involvement of TOR in plant photosynthesis. The recent development of tools for the functional analysis of plant TOR has helped to uncover the involvement of TOR signaling in several steps preceding photoautotrophy and maintenance of photosynthesis. Here, we present recent novel findings relating to TOR signaling and its roles in regulating plant photosynthesis, including carbon nutrient sense, light absorptions, and leaf and chloroplast development. We also provide some gaps in our understanding of TOR function in photosynthesis that need to be addressed in the future.
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Affiliation(s)
- Yun Song
- School of Life Sciences, Liaocheng University, Liaocheng 252000, China;
| | - Mohammed Salem Alyafei
- Department of Integrative Agriculture, College of Food and Agriculture, United Arab Emirates University, Al Ain 15551, United Arab Emirates; (M.S.A.); (K.M.); (A.J.)
| | - Khaled Masmoudi
- Department of Integrative Agriculture, College of Food and Agriculture, United Arab Emirates University, Al Ain 15551, United Arab Emirates; (M.S.A.); (K.M.); (A.J.)
| | - Abdul Jaleel
- Department of Integrative Agriculture, College of Food and Agriculture, United Arab Emirates University, Al Ain 15551, United Arab Emirates; (M.S.A.); (K.M.); (A.J.)
| | - Maozhi Ren
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610213, China
- Correspondence: ; Tel.: +86-13527313471
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15
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Avilan L, Lebrun R, Puppo C, Citerne S, Cuiné S, Li‐Beisson Y, Menand B, Field B, Gontero B. ppGpp influences protein protection, growth and photosynthesis in Phaeodactylum tricornutum. THE NEW PHYTOLOGIST 2021; 230:1517-1532. [PMID: 33595847 PMCID: PMC8252717 DOI: 10.1111/nph.17286] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 02/08/2021] [Indexed: 05/08/2023]
Abstract
Chloroplasts retain elements of a bacterial stress response pathway that is mediated by the signalling nucleotides guanosine penta- and tetraphosphate ((p)ppGpp). In the model flowering plant Arabidopsis, ppGpp acts as a potent regulator of plastid gene expression and influences photosynthesis, plant growth and development. However, little is known about ppGpp metabolism or its evolution in other photosynthetic eukaryotes. Here, we studied the function of ppGpp in the diatom Phaeodactylum tricornutum using transgenic lines containing an inducible system for ppGpp accumulation. We used these lines to investigate the effects of ppGpp on growth, photosynthesis, lipid metabolism and protein expression. We demonstrate that ppGpp accumulation reduces photosynthetic capacity and promotes a quiescent-like state with reduced proliferation and ageing. Strikingly, using nontargeted proteomics, we discovered that ppGpp accumulation also leads to the coordinated upregulation of a protein protection response in multiple cellular compartments. Our findings highlight the importance of ppGpp as a fundamental regulator of chloroplast function across different domains of life, and lead to new questions about the molecular mechanisms and roles of (p)ppGpp signalling in photosynthetic eukaryotes.
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Affiliation(s)
- Luisana Avilan
- CNRSBIPUMR 7281IMM FR 3479Aix Marseille Univ31 Chemin Joseph AiguierMarseille13009France
- Centre for Enzyme InnovationSchool of Biological SciencesInstitute of Biological and Biomedical SciencesUniversity of PortsmouthPortsmouthPO1 2DYUK
| | - Regine Lebrun
- Plate‐forme ProtéomiqueMarseille Protéomique (MaP)IMM FR 3479, 31 Chemin Joseph AiguierMarseille13009France
| | - Carine Puppo
- CNRSBIPUMR 7281IMM FR 3479Aix Marseille Univ31 Chemin Joseph AiguierMarseille13009France
| | - Sylvie Citerne
- Institut Jean‐Pierre BourginINRAEAgroParisTechUniversité Paris‐SaclayVersailles78000France
| | - Stephane Cuiné
- CEA, CNRS, UMR7265 BIAMCEA CadaracheAix‐Marseille UnivSaint‐Paul‐lez Durance13108France
| | - Yonghua Li‐Beisson
- CEA, CNRS, UMR7265 BIAMCEA CadaracheAix‐Marseille UnivSaint‐Paul‐lez Durance13108France
| | - Benoît Menand
- CEA, CNRS, UMR7265 BIAMAix‐Marseille UnivMarseille13009France
| | - Ben Field
- CEA, CNRS, UMR7265 BIAMAix‐Marseille UnivMarseille13009France
| | - Brigitte Gontero
- CNRSBIPUMR 7281IMM FR 3479Aix Marseille Univ31 Chemin Joseph AiguierMarseille13009France
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16
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Zhou B, Takahashi S, Takemura T, Tanaka K, Imamura S. Establishment of a firefly luciferase reporter assay system in the unicellular red alga Cyanidioschyzon merolae. J GEN APPL MICROBIOL 2021; 67:42-46. [PMID: 32938840 DOI: 10.2323/jgam.2020.02.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The firefly luciferase (Luc) reporter assay is a powerful tool used to analyze promoter activities in living cells. In this report, we established a firefly Luc reporter assay system in the unicellular model red alga Cyanidioschyzon merolae. A nitrite reductase (NIR) promoter-Luc fusion gene was integrated into the URA5.3 genomic region to construct the C. merolae NIR-Luc strain. Luc activities in the NIR-Luc strain were increased, correlating with the accumulation of endogenous NIR transcripts in response to nitrogen depletion. Luc activity was also significantly increased by the overexpression of the MYB1 gene, which encodes a transcription factor responsible for NIR promoter activation. Thus, our results demonstrate the utility of the Luc reporter system in C. merolae.
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Affiliation(s)
- Baifeng Zhou
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology.,School of Life Science and Technology, Tokyo Institute of Technology
| | - Sota Takahashi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology.,Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology
| | - Tokiaki Takemura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology.,School of Life Science and Technology, Tokyo Institute of Technology
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology
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17
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The Arabidopsis NOT4A E3 ligase promotes PGR3 expression and regulates chloroplast translation. Nat Commun 2021; 12:251. [PMID: 33431870 PMCID: PMC7801604 DOI: 10.1038/s41467-020-20506-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 11/30/2020] [Indexed: 12/14/2022] Open
Abstract
Chloroplast function requires the coordinated action of nuclear- and chloroplast-derived proteins, including several hundred nuclear-encoded pentatricopeptide repeat (PPR) proteins that regulate plastid mRNA metabolism. Despite their large number and importance, regulatory mechanisms controlling PPR expression are poorly understood. Here we show that the Arabidopsis NOT4A ubiquitin-ligase positively regulates the expression of PROTON GRADIENT REGULATION 3 (PGR3), a PPR protein required for translating several thylakoid-localised photosynthetic components and ribosome subunits within chloroplasts. Loss of NOT4A function leads to a strong depletion of cytochrome b6f and NAD(P)H dehydrogenase (NDH) complexes, as well as plastid 30 S ribosomes, which reduces mRNA translation and photosynthetic capacity, causing pale-yellow and slow-growth phenotypes. Quantitative transcriptome and proteome analysis of the not4a mutant reveal it lacks PGR3 expression, and that its molecular defects resemble those of a pgr3 mutant. Furthermore, we show that normal plastid function is restored to not4a through transgenic PGR3 expression. Our work identifies NOT4A as crucial for ensuring robust photosynthetic function during development and stress-response, through promoting PGR3 production and chloroplast translation.
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18
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Pancha I, Chokshi K, Tanaka K, Imamura S. Microalgal Target of Rapamycin (TOR): A Central Regulatory Hub for Growth, Stress Response and Biomass Production. PLANT & CELL PHYSIOLOGY 2020; 61:675-684. [PMID: 32105317 DOI: 10.1093/pcp/pcaa023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 02/17/2020] [Indexed: 06/10/2023]
Abstract
Target of rapamycin (TOR) is an evolutionarily conserved protein kinase that plays an important role in the regulation of cell growth and the sensing of nutrient and energy status in eukaryotes. In yeasts and mammals, the roles of TOR have been very well described and various functions of TOR signaling in plant lineages have also been revealed over the past 20 years. In the case of microalgae, the functions of TOR have been primarily studied in the model green alga Chlamydomonas reinhardtii and were summarized in an earlier single review article. However, the recent development of tools for the functional analysis of TOR has helped to reveal the involvement of TOR in various functions, including autophagy, transcription, translation, accumulation of energy storage molecules, etc., in microalgae. In the present review, we discuss recent novel findings relating to TOR signaling and its roles in microalgae along with relevant information on land plants and also provide details of topics that must be addressed in future studies to reveal how TOR regulates various physiological functions in microalgae.
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Affiliation(s)
- Imran Pancha
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503 Japan
- Department of Biology, SRM University-AP, Amaravati, Andhra Pradesh 522502, India
| | - Kaumeel Chokshi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503 Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503 Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503 Japan
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19
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StABI5 Involved in the Regulation of Chloroplast Development and Photosynthesis in Potato. Int J Mol Sci 2020; 21:ijms21031068. [PMID: 32041112 PMCID: PMC7036812 DOI: 10.3390/ijms21031068] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 01/30/2020] [Accepted: 02/04/2020] [Indexed: 01/04/2023] Open
Abstract
Abscisic acid (ABA) insensitive 5 (ABI5)—a core transcription factor of the ABA signaling pathway—is a basic leucine zipper transcription factor that plays a key role in the regulation of seed germination and early seedling growth. ABI5 interacts with other phytohormone signals to regulate plant growth and development, and stress responses in Arabidopsis, but little is known about the functions of ABI5 in potatoes. Here, we find that StABI5 is involved in the regulation of chloroplast development and photosynthesis. Genetic analysis indicates that StABI5 overexpression transgenic potato lines accelerate dark-induced leaf yellowing and senescence. The chlorophyll contents of overexpressed StABI5 transgenic potato lines were significantly decreased in comparison to those of wild-type Desiree potatoes under dark conditions. Additionally, the RNA-sequencing (RNA-seq) analysis shows that many metabolic processes are changed in overexpressed StABI5 transgenic potatoes. Most of the genes involved in photosynthesis and carbon fixation are significantly down-regulated, especially the chlorophyll a-b binding protein, photosystem I, and photosystem II. These observations indicate that StABI5 negatively regulates chloroplast development and photosynthesis, and provides some insights into the functions of StABI5 in regard to potato growth.
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20
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RSH enzyme diversity for (p)ppGpp metabolism in Phaeodactylum tricornutum and other diatoms. Sci Rep 2019; 9:17682. [PMID: 31776430 PMCID: PMC6881373 DOI: 10.1038/s41598-019-54207-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 11/05/2019] [Indexed: 12/28/2022] Open
Abstract
The nucleotides guanosine tetraphosphate and pentaphosphate (together known as (p)ppGpp or magic spot) are produced in plant plastids from GDP/GTP and ATP by RelA-SpoT homologue (RSH) enzymes. In the model plant Arabidopsis (p)ppGpp regulates chloroplast transcription and translation to affect growth, and is also implicated in acclimation to stress. However, little is known about (p)ppGpp metabolism or its evolution in other photosynthetic eukaryotes. Here we studied (p)ppGpp metabolism in the marine diatom Phaeodactylum tricornutum. We identified three expressed RSH genes in the P. tricornutum genome, and determined the enzymatic activity of the corresponding enzymes by heterologous expression in bacteria. We showed that two P. tricornutum RSH are (p)ppGpp synthetases, despite substitution of a residue within the active site believed critical for activity, and that the third RSH is a bifunctional (p)ppGpp synthetase and hydrolase, the first of its kind demonstrated in a photosynthetic eukaryote. A broad phylogenetic analysis then showed that diatom RSH belong to novel algal RSH clades. Together our work significantly expands the horizons of (p)ppGpp signalling in the photosynthetic eukaryotes by demonstrating an unexpected functional, structural and evolutionary diversity in RSH enzymes from organisms with plastids derived from red algae.
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21
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Identification of a chloroplast fatty acid exporter protein, CmFAX1, and triacylglycerol accumulation by its overexpression in the unicellular red alga Cyanidioschyzon merolae. ALGAL RES 2019. [DOI: 10.1016/j.algal.2018.101396] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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22
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Pancha I, Shima H, Higashitani N, Igarashi K, Higashitani A, Tanaka K, Imamura S. Target of rapamycin-signaling modulates starch accumulation via glycogenin phosphorylation status in the unicellular red alga Cyanidioschyzon merolae. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 97:485-499. [PMID: 30351485 DOI: 10.1111/tpj.14136] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 09/23/2018] [Accepted: 10/15/2018] [Indexed: 06/08/2023]
Abstract
The target of rapamycin (TOR) signaling pathway is involved in starch accumulation in various eukaryotic organisms; however, the molecular mechanism behind this phenomenon in eukaryotes has not been elucidated. We report a regulatory mechanism of starch accumulation by TOR in the unicellular red alga, Cyanidioschyzon merolae. The starch content in C. merolae after TOR-inactivation by rapamycin, a TOR-specific inhibitor, was increased by approximately 10-fold in comparison with its drug vehicle, dimethyl sulfoxide. However, our previous transcriptome analysis showed that the expression level of genes related to carbohydrate metabolism was unaffected by rapamycin, indicating that starch accumulation is regulated at post-transcriptional levels. In this study, we performed a phosphoproteome analysis using liquid chromatography-tandem mass spectrometry to investigate potential post-transcriptional modifications, and identified 52 proteins as candidate TOR substrates. Among the possible substrates, we focused on the function of CmGLG1, because its phosphorylation at the Ser613 residue was decreased after rapamycin treatment, and overexpression of CmGLG1 resulted in a 4.7-fold higher starch content. CmGLG1 is similar to the priming protein, glycogenin, which is required for the initiation of starch/glycogen synthesis, and a budding yeast complementation assay demonstrated that CmGLG1 can functionally substitute for glycogenin. We found an approximately 60% reduction in the starch content in a phospho-mimicking CmGLG1 overexpression strain, in which Ser613 was substituted with aspartic acid, in comparison with the wild-type CmGLG1 overexpression cells. Our results indicate that TOR modulates starch accumulation by changing the phosphorylation status of the CmGLG1 Ser613 residue in C. merolae.
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Affiliation(s)
- Imran Pancha
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Hiroki Shima
- Department of Biochemistry, Tohoku University Graduate School of Medicine, Seiryo-machi 2-1, Aoba-ku, Sendai, 980-8575, Japan
| | - Nahoko Higashitani
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Kazuhiko Igarashi
- Department of Biochemistry, Tohoku University Graduate School of Medicine, Seiryo-machi 2-1, Aoba-ku, Sendai, 980-8575, Japan
| | - Atsushi Higashitani
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
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23
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Takemura T, Imamura S, Kobayashi Y, Tanaka K. Construction of a Selectable Marker Recycling System and the Use in Epitope Tagging of Multiple Nuclear Genes in the Unicellular Red Alga Cyanidioschyzon merolae. PLANT & CELL PHYSIOLOGY 2018; 59:2308-2316. [PMID: 30099537 DOI: 10.1093/pcp/pcy156] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 07/30/2018] [Indexed: 06/08/2023]
Abstract
The nuclear genome of the unicellular red alga Cyanidioschyzon merolae can be modified by homologous recombination with exogenously introduced DNA. However, it is presently difficult to modify multiple chromosome loci because of the limited number of available positive selectable markers. In this study, we constructed a modified URA5.3 gene (URA5.3T), which can be repeatedly used for nuclear genome transformation, as well as two plasmid vectors for 3× FLAG- or 3× Myc-epitope tagging of nuclear-encoded proteins using URA5.3T. In the URA5.3T marker, the promoter region and open reading frame were located between directly repeated URA5.3 terminator sequences, and the URA5.3 gene can be eliminated by 5-fluoroorotic acid selection through homologous recombination. To demonstrate the utility of the constructed system, a 3× FLAG-tag and 3× Myc-tag were introduced at the C-termini of two of the six Rab proteins in C. merolae, CmRab18 and CmRab7, respectively, and the differential expression levels were successfully monitored by immunoblot analysis using these epitope tags. The URA5.3T marker's introduction and elimination cycle can be repeated. Thus, we have constructed a marker recycling system for C. merolae nuclear transformation. A novel procedure to obtain a high plating efficiency of C. merolae cells on solid gellan gum plates is also presented.
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Affiliation(s)
- Tokiaki Takemura
- Laboratory for Chemistry and Life Science, Institute of Innovative Science, Tokyo Institute of Technology, Nagatsuta, Yokohama, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta, Yokohama, Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Science, Tokyo Institute of Technology, Nagatsuta, Yokohama, Japan
| | - Yuki Kobayashi
- Laboratory for Chemistry and Life Science, Institute of Innovative Science, Tokyo Institute of Technology, Nagatsuta, Yokohama, Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Science, Tokyo Institute of Technology, Nagatsuta, Yokohama, Japan
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24
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Accelerated triacylglycerol production without growth inhibition by overexpression of a glycerol-3-phosphate acyltransferase in the unicellular red alga Cyanidioschyzon merolae. Sci Rep 2018; 8:12410. [PMID: 30120352 PMCID: PMC6098107 DOI: 10.1038/s41598-018-30809-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 08/04/2018] [Indexed: 12/14/2022] Open
Abstract
Microalgae accumulate triacylglycerols (TAGs), a promising feedstock for biodiesel production, under unfavorable environmental or stress conditions for their growth. Our previous analyses revealed that only transcripts of CmGPAT1 and CmGPAT2, both encoding glycerol-3-phosphate acyltransferase, were increased among fatty acid and TAG synthesis genes under TAG accumulation conditions in the red alga Cyanidioschyzon merolae. In this study, to investigate the role of these proteins in TAG accumulation in C. merolae, we constructed FLAG-fused CmGPAT1 and CmGPAT2 overexpression strains. We found that CmGPAT1 overexpression resulted in marked accumulation of TAG even under normal growth conditions, with the maximum TAG productivity increased 56.1-fold compared with the control strain, without a negative impact on algal growth. The relative fatty acid composition of 18:2 in the TAGs and the sn-1/sn-3 positions were significantly increased compared with the control strain, suggesting that CmGPAT1 had a substrate preference for 18:2. Immunoblot analysis after cell fractionation and immunostaining analysis demonstrated that CmGPAT1 localizes in the endoplasmic reticulum (ER). These results indicate that the reaction catalyzed by the ER-localized CmGPAT1 is a rate-limiting step for TAG synthesis in C. merolae, and would be a potential target for improvement of TAG productivity in microalgae.
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25
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Bechtold U, Field B. Molecular mechanisms controlling plant growth during abiotic stress. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:2753-2758. [PMID: 29788471 PMCID: PMC5961130 DOI: 10.1093/jxb/ery157] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Affiliation(s)
- Ulrike Bechtold
- School of Biological Sciences, University of Essex, Colchester UK
- Correspondence: or
| | - Benjamin Field
- Aix Marseille Univ, CEA, CNRS, UMR7265 BVME, Marseille, France
- Correspondence: or
| |
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