1
|
Komiya S, Pancha I, Shima H, Igarashi K, Tanaka K, Imamura S. Target of rapamycin signaling regulates starch degradation via α-glucan water dikinase in a unicellular red alga. PLANT PHYSIOLOGY 2025; 197:kiaf106. [PMID: 40112858 PMCID: PMC11986951 DOI: 10.1093/plphys/kiaf106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2025] [Accepted: 02/07/2025] [Indexed: 03/22/2025]
Abstract
Target of rapamycin (TOR) signaling pathways are major regulators of starch accumulation in various eukaryotes. However, the underlying molecular mechanisms of this regulation remain elusive. Here, we report the role of TOR signaling in starch degradation in the unicellular red alga Cyanidioschyzon merolae. Reanalysis of our previously published phosphoproteome data showed that phosphorylation of the serine residue at position 264 of a protein similar to α-glucan water dikinase (CmGWD), a key regulator of starch degradation, was not increased by rapamycin treatment. In the CmGWD knockout strain, starch content increased and starch phosphorylation decreased, indicating that CmGWD is a functional GWD. CmGWD-dependent starch degradation under dark conditions was alleviated by rapamycin treatment. The overexpression of a phosphomimic CmGWD variant, in which Ser264 was replaced by aspartic acid, or a dephosphomimic CmGWD variant, in which Ser264 was replaced by alanine, resulted in 0.6-fold lower and 1.6-fold higher starch accumulation compared to the wild-type CmGWD-overexpressing strain, respectively. The starch levels corresponded with starch phosphorylation status. Furthermore, the dephosphomimic CmGWD-overexpressing strain accumulated nearly the same amount of starch with or without rapamycin treatment as the rapamycin-treated wild-type CmGWD-overexpressing strain. In contrast, rapamycin treatment did not trigger an increase in starch accumulation in the phosphomimic CmGWD-overexpressing strain. These results indicate that TOR signaling regulates starch degradation in C. merolae by altering the phosphorylation state of Ser264 in CmGWD.
Collapse
Affiliation(s)
- Sota Komiya
- Laboratory for Chemistry and Life Science, Institute of Integrated Research, Institute of Science Tokyo, 4259-R1 Nagatsutacho, Midori-ku, Yokohama 226-8503, Japan
| | - Imran Pancha
- Laboratory for Chemistry and Life Science, Institute of Integrated Research, Institute of Science Tokyo, 4259-R1 Nagatsutacho, Midori-ku, Yokohama 226-8503, Japan
- Department of Industrial Biotechnology, Gujarat Biotechnology University, Gandhinagar, Gujarat 382355, India
| | - Hiroki Shima
- Department of Biochemistry, Tohoku University Graduate School of Medicine, Seiryo-machi 2-1, Aoba-ku, Sendai 980-8575, Japan
| | - Kazuhiko Igarashi
- Department of Biochemistry, Tohoku University Graduate School of Medicine, Seiryo-machi 2-1, Aoba-ku, Sendai 980-8575, Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Integrated Research, Institute of Science Tokyo, 4259-R1 Nagatsutacho, Midori-ku, Yokohama 226-8503, Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute of Integrated Research, Institute of Science Tokyo, 4259-R1 Nagatsutacho, Midori-ku, Yokohama 226-8503, Japan
- Space Environment and Energy Laboratories, NTT Corporation, Musashino-shi, Tokyo 180-8585, Japan
| |
Collapse
|
2
|
Villegas-Valencia M, Stark MR, Seger M, Wellman GB, Overmans S, Lammers PJ, Rader SD, Lauersen KJ. A rapid CAT transformation protocol and nuclear transgene expression tools for metabolic engineering in Cyanidioschyzon merolae 10D. N Biotechnol 2025; 85:39-51. [PMID: 39638031 DOI: 10.1016/j.nbt.2024.12.001] [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: 08/13/2024] [Revised: 12/02/2024] [Accepted: 12/02/2024] [Indexed: 12/07/2024]
Abstract
The eukaryotic red alga Cyanidioschyzon merolae 10D is an emerging algal host for synthetic biology and metabolic engineering. Its small nuclear genome (16.5 Mb; 4775 genes), low intron content (39), stable transgene expression, and capacity for homologous recombination into its nuclear genome make it ideal for genetic and metabolic engineering endeavors. Here, we present an optimized transformation and selection protocol, which yields single chloramphenicol-resistant transformants in under two weeks. Transformation dynamics and a synthetic modular plasmid toolkit are reported, including several new fluorescent reporters. Techniques for fluorescence reporter imaging and analysis at different scales are presented to facilitate high-throughput screening of C. merolae transformants. We use this plasmid toolkit to overexpress the Ipomoea batatas isoprene synthase and demonstrate the dynamics of engineered volatile isoprene production during different light regimes using multi-port headspace analysis coupled to parallel photobioreactors. This work seeks to promote C. merolae as an algal system for metabolic engineering and future sustainable biotechnological production.
Collapse
Affiliation(s)
- Melany Villegas-Valencia
- Bioengineering Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Martha R Stark
- Department of Chemistry and Biochemistry, University of Northern British Columbia, Prince George, Canada
| | - Mark Seger
- Arizona Center for Algae Technology and Innovation, Arizona State University, Mesa, United States
| | - Gordon B Wellman
- Bioengineering Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Sebastian Overmans
- Bioengineering Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Peter J Lammers
- Arizona Center for Algae Technology and Innovation, Arizona State University, Mesa, United States
| | - Stephen D Rader
- Department of Chemistry and Biochemistry, University of Northern British Columbia, Prince George, Canada
| | - Kyle J Lauersen
- Bioengineering Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia; Arizona Center for Algae Technology and Innovation, Arizona State University, Mesa, United States.
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Kobayashi I, Imamura S, Hirota R, Kuroda A, Tanaka K. Expression of bacterial phosphite dehydrogenase confers phosphite availability in a unicellular red alga Cyanidioschyzon merolae. J GEN APPL MICROBIOL 2024; 69:287-291. [PMID: 37587047 DOI: 10.2323/jgam.2023.08.002] [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] [Indexed: 08/18/2023]
Abstract
Microalgae are promising cell factories for producing value-added products. Large-scale microalgal cultivation suffers from invasion by contaminating microorganisms. Since most contaminating organisms cannot utilize phosphite as a unique phosphorus source, phosphite-utilizing ability may provide a growth advantage against contaminating organisms and solve this problem. Studies showed that microorganisms, typically unable to metabolize phosphite, can utilize phosphite by expressing exogenous phosphite dehydrogenase. Here, we constructed Cyanidioschyzon merolae strains introduced with the phosphite dehydrogenase gene, ptxD, from Ralstonia sp. 4506. The ptxD-introduced strains grew in a phosphite-dependent manner, with the phosphite-related growth rate almost matching that with phosphate as sole phosphorus source.
Collapse
Affiliation(s)
- Ikki Kobayashi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology
| | - Sousuke Imamura
- Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation
| | - Ryuichi Hirota
- Unit of Biotechnology, Graduate School of Integrated Sciences for Life, Hiroshima University
| | - Akio Kuroda
- Unit of Biotechnology, Graduate School of Integrated Sciences for Life, Hiroshima University
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology
| |
Collapse
|
5
|
Han SJ, Jiang YL, You LL, Shen LQ, Wu X, Yang F, Cui N, Kong WW, Sun H, Zhou K, Meng HC, Chen ZP, Chen Y, Zhang Y, Zhou CZ. DNA looping mediates cooperative transcription activation. Nat Struct Mol Biol 2024; 31:293-299. [PMID: 38177666 DOI: 10.1038/s41594-023-01149-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 10/04/2023] [Indexed: 01/06/2024]
Abstract
Transcription factors respond to multilevel stimuli and co-occupy promoter regions of target genes to activate RNA polymerase (RNAP) in a cooperative manner. To decipher the molecular mechanism, here we report two cryo-electron microscopy structures of Anabaena transcription activation complexes (TACs): NtcA-TAC composed of RNAP holoenzyme, promoter and a global activator NtcA, and NtcA-NtcB-TAC comprising an extra context-specific regulator, NtcB. Structural analysis showed that NtcA binding makes the promoter DNA bend by ∼50°, which facilitates RNAP to contact NtcB at the distal upstream NtcB box. The sequential binding of NtcA and NtcB induces looping back of promoter DNA towards RNAP, enabling the assembly of a fully activated TAC bound with two activators. Together with biochemical assays, we propose a 'DNA looping' mechanism of cooperative transcription activation in bacteria.
Collapse
Affiliation(s)
- Shu-Jing Han
- School of Life Sciences and Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science & Technology of China, Hefei, China
| | - Yong-Liang Jiang
- School of Life Sciences and Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science & Technology of China, Hefei, China.
| | - Lin-Lin You
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Li-Qiang Shen
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Xiaoxian Wu
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Feng Yang
- School of Life Sciences and Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science & Technology of China, Hefei, China
| | - Ning Cui
- School of Life Sciences and Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science & Technology of China, Hefei, China
| | - Wen-Wen Kong
- School of Life Sciences and Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science & Technology of China, Hefei, China
| | - Hui Sun
- School of Life Sciences and Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science & Technology of China, Hefei, China
| | - Ke Zhou
- School of Life Sciences and Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science & Technology of China, Hefei, China
| | - Hui-Chao Meng
- School of Life Sciences and Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science & Technology of China, Hefei, China
| | - Zhi-Peng Chen
- School of Life Sciences and Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science & Technology of China, Hefei, China
| | - Yuxing Chen
- School of Life Sciences and Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science & Technology of China, Hefei, China
| | - Yu Zhang
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
| | - Cong-Zhao Zhou
- School of Life Sciences and Biomedical Sciences and Health Laboratory of Anhui Province, Division of Life Sciences and Medicine, University of Science & Technology of China, Hefei, China.
| |
Collapse
|
6
|
Krupnik T. Factors affecting light harvesting in the red alga Cyanidioschyzon merolae. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2023; 336:111854. [PMID: 37659734 DOI: 10.1016/j.plantsci.2023.111854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/24/2023] [Accepted: 08/29/2023] [Indexed: 09/04/2023]
Abstract
The phycobilisome antennas, which contain phycobilin pigments instead of chlorophyll, are crucial for the photosynthetic activity of Cyanidioschyzon merolae cells, which thrive in an acidic and hot water environment. The accessible light intensity and quality, temperature, acidity, and other factors in this environment are quite different from those in the air available for terrestrial plants. Under these conditions, adaptation to the intensity and quality of light, as well as temperature, which are key factors in photosynthesis of higher plants, also affects this process in Cyanidioschyzon merolae cells. Adaptation to varying light conditions requires fast remodeling and re-tuning of their light-harvesting antennas (phycobilisomes) at multiple levels, from regulation of gene expression to structural reorganization of protein-pigment complexes. This review presents selected data on the structure of phycobilisomes, the genetic engineering of the constituent proteins, and the latest results and opinions on the adaptation of phycobilisomes to light intensity and quality, and temperature to photosynthetic activities. We pay special attention to the latest results of the C. merolae research.
Collapse
Affiliation(s)
- Tomasz Krupnik
- Department of Molecular Plant Physiology, Institute of Environmental Biology, Faculty of Biology, University of Warsaw, Miecznikowa 1, Warsaw 02096, Poland.
| |
Collapse
|
7
|
Shi X, Tan W, Tang S, Ling Q, Tang C, Qin P, Luo S, Zhao Y, Yu F, Li Y. Metagenomics reveals taxon-specific responses of soil nitrogen cycling under different fertilization regimes in heavy metal contaminated soil. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 345:118766. [PMID: 37579601 DOI: 10.1016/j.jenvman.2023.118766] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 07/24/2023] [Accepted: 08/09/2023] [Indexed: 08/16/2023]
Abstract
Soil deficiency, cyclic erosion, and heavy metal pollution have led to fertility loss and ecological function decline in mining areas. Fertilization is an important way to rapidly replenish soil nutrients, which have a major influence on the soil nitrogen cycling process, but different fertilization regimes have different impacts on soil properties and microbial functional potentials. Here, metagenomic sequencing was used to investigate the different responses of key functional genes of microbial nitrogen cycling to fertilization regimes and explore the potential effects of soil physicochemical properties on the key functional genes. The results indicated that AC-HH (ammonium chloride-high frequency and concentration) treatment significantly increased the gene abundance of norC (13.40-fold), nirK (5.46-fold), and napA (5.37-fold). U-HH (urea-high frequency and concentration) treatment significantly increased the gene abundance of hao (6.24-fold), pmoA-amoA (4.32-fold) norC (7.00-fold), nosZ (3.69-fold), and nirK (6.88-fold). Functional genes were distributed differently among the 10 dominant phyla. The nifH and nifK genes were distributed only in Proteobacteria. The hao gene was distributed in Gemmatimonadetes, Nitrospirae and Proteobacteria. Fertilization regimes caused changes in functional redundancy in soil, and nirK and nirB, which are involved in denitrification, were present in different genera. Fertilization regimes with high frequency and high concentration were more likely to increase the gene abundance at the genus level. In summary, this study provides insights into the taxon-specific response of soil nitrogen cycling under different fertilization regimes, where changes in fertilization regimes affect microbial nitrogen cycling by altering soil physicochemical properties in a complex dynamic environment.
Collapse
Affiliation(s)
- Xinwei Shi
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China
| | - Weilan Tan
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China
| | - Shuting Tang
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China
| | - Qiujie Ling
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China
| | - Chijian Tang
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China
| | - Peiqing Qin
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China
| | - Shiyu Luo
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China
| | - Yinjun Zhao
- Key Laboratory of Environment Change and Resources Use in Beibu Gulf, Ministry of Education, Nanning Normal University, Nanning, China
| | - Fangming Yu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China.
| | - Yi Li
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Environment and Resources, Guangxi Normal University, 541004, Guilin, China.
| |
Collapse
|
8
|
Hisanaga T, Romani F, Wu S, Kowar T, Wu Y, Lintermann R, Fridrich A, Cho CH, Chaumier T, Jamge B, Montgomery SA, Axelsson E, Akimcheva S, Dierschke T, Bowman JL, Fujiwara T, Hirooka S, Miyagishima SY, Dolan L, Tirichine L, Schubert D, Berger F. The Polycomb repressive complex 2 deposits H3K27me3 and represses transposable elements in a broad range of eukaryotes. Curr Biol 2023; 33:4367-4380.e9. [PMID: 37738971 DOI: 10.1016/j.cub.2023.08.073] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 06/19/2023] [Accepted: 08/24/2023] [Indexed: 09/24/2023]
Abstract
The mobility of transposable elements (TEs) contributes to evolution of genomes. Their uncontrolled activity causes genomic instability; therefore, expression of TEs is silenced by host genomes. TEs are marked with DNA and H3K9 methylation, which are associated with silencing in flowering plants, animals, and fungi. However, in distantly related groups of eukaryotes, TEs are marked by H3K27me3 deposited by the Polycomb repressive complex 2 (PRC2), an epigenetic mark associated with gene silencing in flowering plants and animals. The direct silencing of TEs by PRC2 has so far only been shown in one species of ciliates. To test if PRC2 silences TEs in a broader range of eukaryotes, we generated mutants with reduced PRC2 activity and analyzed the role of PRC2 in extant species along the lineage of Archaeplastida and in the diatom P. tricornutum. In this diatom and the red alga C. merolae, a greater proportion of TEs than genes were repressed by PRC2, whereas a greater proportion of genes than TEs were repressed by PRC2 in bryophytes. In flowering plants, TEs contained potential cis-elements recognized by transcription factors and associated with neighbor genes as transcriptional units repressed by PRC2. Thus, silencing of TEs by PRC2 is observed not only in Archaeplastida but also in diatoms and ciliates, suggesting that PRC2 deposited H3K27me3 to silence TEs in the last common ancestor of eukaryotes. We hypothesize that during the evolution of Archaeplastida, TE fragments marked with H3K27me3 were selected to shape transcriptional regulation, controlling networks of genes regulated by PRC2.
Collapse
Affiliation(s)
- Tetsuya Hisanaga
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Facundo Romani
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK
| | - Shuangyang Wu
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Teresa Kowar
- Epigenetics of Plants, Institute of Biology, Freie Universität Berlin, 14195 Berlin, Germany
| | - Yue Wu
- Nantes Université, CNRS, US2B, UMR 6286, 44000 Nantes, France
| | - Ruth Lintermann
- Epigenetics of Plants, Institute of Biology, Freie Universität Berlin, 14195 Berlin, Germany
| | - Arie Fridrich
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Chung Hyun Cho
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Dr. Bohr-Gasse 3, 1030 Vienna, Austria; Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, South Korea
| | | | - Bhagyshree Jamge
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Dr. Bohr-Gasse 3, 1030 Vienna, Austria; Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, 1030 Vienna, Austria
| | - Sean A Montgomery
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Dr. Bohr-Gasse 3, 1030 Vienna, Austria; Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, 1030 Vienna, Austria
| | - Elin Axelsson
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Svetlana Akimcheva
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Tom Dierschke
- School of Biological Sciences, Monash University, Melbourne, VIC 3800, Australia
| | - John L Bowman
- School of Biological Sciences, Monash University, Melbourne, VIC 3800, Australia; ARC Centre of Excellence for Plant Success in Nature and Agriculture, Monash University, Clayton, Melbourne, VIC 3800, Australia
| | - Takayuki Fujiwara
- Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan; Department of Genetics, Graduate University for Advanced Studies, SOKENDAI, Mishima, Shizuoka 411-8540, Japan
| | - Shunsuke Hirooka
- Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan; Department of Genetics, Graduate University for Advanced Studies, SOKENDAI, Mishima, Shizuoka 411-8540, Japan
| | - Shin-Ya Miyagishima
- Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan; Department of Genetics, Graduate University for Advanced Studies, SOKENDAI, Mishima, Shizuoka 411-8540, Japan
| | - Liam Dolan
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Leila Tirichine
- Nantes Université, CNRS, US2B, UMR 6286, 44000 Nantes, France
| | - Daniel Schubert
- Epigenetics of Plants, Institute of Biology, Freie Universität Berlin, 14195 Berlin, Germany.
| | - Frédéric Berger
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Dr. Bohr-Gasse 3, 1030 Vienna, Austria.
| |
Collapse
|
9
|
AKGÜL F, AKGÜL R. Combined effect of nitrogen and phosphorus on growth and biochemical composition of Tetradesmus obliquus (Turpin) M.J. Wynne. INTERNATIONAL JOURNAL OF SECONDARY METABOLITE 2022. [DOI: 10.21448/ijsm.1102592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Microalgae have many biotechnological applications in various industries including food and feed, fertilizer, biofuel, cosmetics, pharmaceutics, and wastewater treatment. Since hey produce secondary metabolites under stress conditions such as pigments, carotenoids, hydrocarbons, and vitamins, investigating the effects of stress factors on growth parameters and biochemical composition of microalgal biomass is needed in producing bioproducts.
In this paper, the combined effects of nitrogen and phosphorus on growth and the protein/amino acid and Lipid-FAMEs profiles of microalgae Tetradesmus obliquus (MAKUMACC-037) were investigated.
Nitrogen and phosphorus deficiency reduced the algal growth. Biochemical composition was changed in a nitrogen and phosphorus dependent manner.
High concentration of protein and lipid were associated with increased nitrogen and phosphorus concentration However, the FAMEs profiles were changed depending on only the nitrogen concentration.
Collapse
Affiliation(s)
- Füsun AKGÜL
- MEHMET AKİF ERSOY ÜNİVERSİTESİ, FEN-EDEBİYAT FAKÜLTESİ
| | | |
Collapse
|
10
|
Takeue N, Kuroyama A, Hayashi Y, Tanaka K, Imamura S. Autofluorescence-based high-throughput isolation of nonbleaching Cyanidioschyzon merolae strains under nitrogen-depletion. FRONTIERS IN PLANT SCIENCE 2022; 13:1036839. [PMID: 36589047 PMCID: PMC9794624 DOI: 10.3389/fpls.2022.1036839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
Photosynthetic organisms maintain optimum levels of photosynthetic pigments in response to environmental changes to adapt to the conditions. The identification of cyanobacteria strains that alleviate bleaching has revealed genes that regulate levels of phycobilisome, the main light-harvesting complex. In contrast, the mechanisms of pigment degradation in algae remain unclear, as no nonbleaching strains have previously been isolated. To address this issue, this study attempted to isolate nonbleaching strains of the unicellular red alga Cyanidioschyzon merolae after exposure to nitrogen (N)-depletion based on autofluorescence information. After four weeks under N-depletion, 13 cells from 500,000 cells with almost identical pre- and post-depletion chlorophyll a (Chl a) and/or phycocyanin autofluorescence intensities were identified. These nonbleaching candidate strains were sorted via a cell sorter, isolated on solid medium, and their post-N-depletion Chl a and phycocyanin levels were analyzed. Chl a levels of these nonbleaching candidate strains were lower at 1-4 weeks of N-depletion similar to the control strains, however, their phycocyanin levels were unchanged. Thus, we successfully isolated nonbleaching C. merolae strains in which phycocyanin was not degraded under N-depletion, via autofluorescence spectroscopy and cell sorting. This versatile method will help to elucidate the mechanisms regulating pigments in microalgae.
Collapse
Affiliation(s)
- Nozomi Takeue
- School of Life Science and Technology, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
| | - Ayaka Kuroyama
- Product and Business Planning Section, Planning and Marketing Department, Life Science Business Division, Medical Business Group, Sony Corporation, Nishi-ku, Yokohama, Japan
| | - Yoshiharu Hayashi
- Product and Business Planning Section, Planning and Marketing Department, Life Science Business Division, Medical Business Group, Sony Corporation, Nishi-ku, Yokohama, Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
- Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation, Musashino-shi, Tokyo, Japan
| |
Collapse
|
11
|
Maeno T, Yamakawa Y, Takiyasu Y, Miyauchi H, Nakamura Y, Ono M, Ozaki N, Utsumi Y, Cenci U, Colleoni C, Ball S, Tsuzuki M, Fujiwara S. One of the isoamylase isoforms, CMI294C, is required for semi-amylopectin synthesis in the rhodophyte Cyanidioschyzon merolae. FRONTIERS IN PLANT SCIENCE 2022; 13:967165. [PMID: 36051298 PMCID: PMC9424615 DOI: 10.3389/fpls.2022.967165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Most rhodophytes synthesize semi-amylopectin as a storage polysaccharide, whereas some species in the most primitive class (Cyanidiophyceae) make glycogen. To know the roles of isoamylases in semi-amylopectin synthesis, we investigated the effects of isoamylase gene (CMI294C and CMS197C)-deficiencies on semi-amylopectin molecular structure and starch granule morphology in Cyanidioschyzon merolae (Cyanidiophyceae). Semi-amylopectin content in a CMS197C-disruption mutant (ΔCMS197C) was not significantly different from that in the control strain, while that in a CMI294C-disruption mutant (ΔCMI294C) was much lower than those in the control strain, suggesting that CMI294C is essential for semi-amylopectin synthesis. Scanning electron microscopy showed that the ΔCMI294C strain contained smaller starch granules, while the ΔCMS197C strain had normal size, but donut-shaped granules, unlike those of the control strain. Although the chain length distribution of starch from the control strain displayed a semi-amylopectin pattern with a peak around degree of polymerization (DP) 11-13, differences in chain length profiles revealed that the ΔCMS197C strain has more short chains (DP of 3 and 4) than the control strain, while the ΔCMI294C strain has more long chains (DP ≥12). These findings suggest that CMI294C-type isoamylase, which can debranch a wide range of chains, probably plays an important role in semi-amylopectin synthesis unique in the Rhodophyta.
Collapse
Affiliation(s)
- Toshiki Maeno
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Yuki Yamakawa
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Yohei Takiyasu
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Hiroki Miyauchi
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Yasunori Nakamura
- Faculty of Bioresource Sciences, Akita Prefectural University, Akita, Japan
| | - Masami Ono
- Faculty of Bioresource Sciences, Akita Prefectural University, Akita, Japan
| | - Noriaki Ozaki
- Faculty of Bioresource Sciences, Akita Prefectural University, Akita, Japan
| | | | - Ugo Cenci
- CNRS, UMR8576-UGSF-Unite de Glycobiologie Structurale et Fonctionnelle, University of Lille, Lille, France
| | - Christophe Colleoni
- CNRS, UMR8576-UGSF-Unite de Glycobiologie Structurale et Fonctionnelle, University of Lille, Lille, France
| | - Steven Ball
- CNRS, UMR8576-UGSF-Unite de Glycobiologie Structurale et Fonctionnelle, University of Lille, Lille, France
| | - Mikio Tsuzuki
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| | - Shoko Fujiwara
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Japan
| |
Collapse
|
12
|
Zhou B, Shima H, Igarashi K, Tanaka K, Imamura S. CmNDB1 and a Specific Domain of CmMYB1 Negatively Regulate CmMYB1-Dependent Transcription of Nitrate Assimilation Genes Under Nitrogen-Repleted Condition in a Unicellular Red Alga. FRONTIERS IN PLANT SCIENCE 2022; 13:821947. [PMID: 35360310 PMCID: PMC8962646 DOI: 10.3389/fpls.2022.821947] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/07/2022] [Indexed: 06/02/2023]
Abstract
Nitrogen assimilation is an essential process that controls plant growth and development. Plant cells adjust the transcription of nitrogen assimilation genes through transcription factors (TFs) to acclimatize to changing nitrogen levels in nature. However, the regulatory mechanisms of these TFs under nitrogen-repleted (+N) conditions in plant lineages remain largely unknown. Here, we identified a negative domain (ND) of CmMYB1, the nitrogen-depleted (-N)-activated TF, in a unicellular red alga Cyanidioschyzon merolae. The ND deletion changed the localization of CmMYB1 from the cytoplasm to the nucleus, enhanced the binding efficiency of CmMYB1 to promoters of nitrate assimilation genes, and increased the transcripts of nitrate assimilation genes under +N condition. A pull-down assay using an ND-overexpressing strain combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis helped us to screen and identify an unknown-function protein, the CmNDB1. Yeast two-hybrid analysis demonstrated that CmNDB1 interacts with ND. Similar to ND deletion, CmNDB1 deletion also led to the nucleus localization of CmMYB1, enhanced the promoter-binding ratio of CmMYB1 to the promoter regions of nitrate assimilation genes, and increased transcript levels of nitrate assimilation genes under +N condition. Thus, these presented results indicated that ND and CmNDB1 negatively regulate CmMYB1 functions under the +N condition in C. merolae.
Collapse
Affiliation(s)
- Baifeng Zhou
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Hiroki Shima
- Department of Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Kazuhiko Igarashi
- Department of Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
- NTT Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation, Tokyo, Japan
| |
Collapse
|
13
|
Fujiwara T, Hirooka S, Miyagishima SY. A cotransformation system of the unicellular red alga Cyanidioschyzon merolae with blasticidin S deaminase and chloramphenicol acetyltransferase selectable markers. BMC PLANT BIOLOGY 2021; 21:573. [PMID: 34863100 PMCID: PMC8642924 DOI: 10.1186/s12870-021-03365-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 11/24/2021] [Indexed: 05/24/2023]
Abstract
BACKGROUND The unicellular red alga Cyanidioschyzon merolae exhibits a very simple cellular and genomic architecture. In addition, procedures for genetic modifications, such as gene targeting by homologous recombination and inducible/repressible gene expression, have been developed. However, only two markers for selecting transformants, uracil synthase (URA) and chloramphenicol acetyltransferase (CAT), are available in this alga. Therefore, manipulation of two or more different chromosomal loci in the same strain in C. merolae is limited. RESULTS This study developed a nuclear targeting and transformant selection system using an antibiotics blasticidin S (BS) and the BS deaminase (BSD) selectable marker by homologous recombination in C. merolae. In addition, this study has succeeded in simultaneously modifying two different chromosomal loci by a single-step cotransformation based on the combination of BSD and CAT selectable markers. A C. merolae strain that expresses mitochondrion-targeted mSCARLET (with the BSD marker) and mVENUS (with the CAT marker) from different chromosomal loci was generated with this procedure. CONCLUSIONS The newly developed BSD selectable marker enables an additional genetic modification to the already generated C. merolae transformants based on the URA or CAT system. Furthermore, the cotransformation system facilitates multiple genetic modifications. These methods and the simple nature of the C. merolae cellular and genomic architecture will facilitate studies on several phenomena common to photosynthetic eukaryotes.
Collapse
Affiliation(s)
- Takayuki Fujiwara
- Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan.
- Department of Genetics, Graduate University for Advanced Studies, SOKENDAI, Mishima, Shizuoka, 411-8540, Japan.
| | - Shunsuke Hirooka
- Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan
| | - Shin-Ya Miyagishima
- Department of Gene Function and Phenomics, National Institute of Genetics, Mishima, Shizuoka, 411-8540, Japan.
- Department of Genetics, Graduate University for Advanced Studies, SOKENDAI, Mishima, Shizuoka, 411-8540, Japan.
| |
Collapse
|
14
|
Miyagishima SY, Tanaka K. The Unicellular Red Alga Cyanidioschyzon merolae-The Simplest Model of a Photosynthetic Eukaryote. PLANT & CELL PHYSIOLOGY 2021; 62:926-941. [PMID: 33836072 PMCID: PMC8504449 DOI: 10.1093/pcp/pcab052] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 04/01/2021] [Indexed: 05/13/2023]
Abstract
Several species of unicellular eukaryotic algae exhibit relatively simple genomic and cellular architecture. Laboratory cultures of these algae grow faster than plants and often provide homogeneous cellular populations exposed to an almost equal environment. These characteristics are ideal for conducting experiments at the cellular and subcellular levels. Many microalgal lineages have recently become genetically tractable, which have started to evoke new streams of studies. Among such algae, the unicellular red alga Cyanidioschyzon merolae is the simplest organism; it possesses the minimum number of membranous organelles, only 4,775 protein-coding genes in the nucleus, and its cell cycle progression can be highly synchronized with the diel cycle. These properties facilitate diverse omics analyses of cellular proliferation and structural analyses of the intracellular relationship among organelles. C. merolae cells lack a rigid cell wall and are thus relatively easily disrupted, facilitating biochemical analyses. Multiple chromosomal loci can be edited by highly efficient homologous recombination. The procedures for the inducible/repressive expression of a transgene or an endogenous gene in the nucleus and for chloroplast genome modification have also been developed. Here, we summarize the features and experimental techniques of C. merolae and provide examples of studies using this alga. From these studies, it is clear that C. merolae-either alone or in comparative and combinatory studies with other photosynthetic organisms-can provide significant insights into the biology of photosynthetic eukaryotes.
Collapse
Affiliation(s)
- Shin-Ya Miyagishima
- * Corresponding authors: Shin-Ya Miyagishima, E-mail: ; Fax, +81-55-981-9412; Kan Tanaka, E-mail:
| | - Kan Tanaka
- * Corresponding authors: Shin-Ya Miyagishima, E-mail: ; Fax, +81-55-981-9412; Kan Tanaka, E-mail:
| |
Collapse
|
15
|
Pancha I, Takaya K, Tanaka K, Imamura S. The Unicellular Red Alga Cyanidioschyzon merolae, an Excellent Model Organism for Elucidating Fundamental Molecular Mechanisms and Their Applications in Biofuel Production. PLANTS 2021; 10:plants10061218. [PMID: 34203949 PMCID: PMC8232737 DOI: 10.3390/plants10061218] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/11/2021] [Accepted: 06/11/2021] [Indexed: 11/16/2022]
Abstract
Microalgae are considered one of the best resources for the production of biofuels and industrially important compounds. Various models have been developed to understand the fundamental mechanism underlying the accumulation of triacylglycerols (TAGs)/starch and to enhance its content in cells. Among various algae, the red alga Cyanidioschyzonmerolae has been considered an excellent model system to understand the fundamental mechanisms behind the accumulation of TAG/starch in the microalga, as it has a smaller genome size and various biotechnological methods are available for it. Furthermore, C. merolae can grow and survive under high temperature (40 °C) and low pH (2–3) conditions, where most other organisms would die, thus making it a choice alga for large-scale production. Investigations using this alga has revealed that the target of rapamycin (TOR) kinase is involved in the accumulation of carbon-reserved molecules, TAGs, and starch. Furthermore, detailed molecular mechanisms of the role of TOR in controlling the accumulation of TAGs and starch were uncovered via omics analyses. Based on these findings, genetic engineering of the key gene and proteins resulted in a drastic increment of the amount of TAGs and starch. In addition to these studies, other trials that attempted to achieve the TAG increment in C. merolae have been summarized in this article.
Collapse
Affiliation(s)
- Imran Pancha
- Department of Biological Sciences, SRM University-AP, Amaravati, Andhra Pradesh 522502, India
- Correspondence: (I.P.); (S.I.); Tel.: +81-422-59-6179 (S.I.)
| | - Kazuhiro Takaya
- NTT Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation, 3-9-11 Midori-cho, Musashino-shi, Tokyo 180-8585, Japan;
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1-29 Nagatsuta, Midori-ku, Yokohama-shi, Kanagawa 226-8503, Japan;
| | - Sousuke Imamura
- NTT Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation, 3-9-11 Midori-cho, Musashino-shi, Tokyo 180-8585, Japan;
- Correspondence: (I.P.); (S.I.); Tel.: +81-422-59-6179 (S.I.)
| |
Collapse
|
16
|
Identification of Transcription Factors and the Regulatory Genes Involved in Triacylglycerol Accumulation in the Unicellular Red Alga Cyanidioschyzon merolae. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10050971. [PMID: 34068121 PMCID: PMC8152781 DOI: 10.3390/plants10050971] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/10/2021] [Accepted: 05/10/2021] [Indexed: 12/30/2022]
Abstract
Microalgal triacylglycerols (TAGs) are a good feedstock for liquid biofuel production. Improving the expression and/or function of transcription factors (TFs) involved in TAG accumulation may increase TAG content; however, information on microalgae is still lacking. In this study, 14 TFs in the unicellular red alga Cyanidioschyzon merolae were identified as candidate TFs regulating TAG accumulation using available transcriptome and phosphoproteome data under conditions driving TAG accumulation. To investigate the roles of these TFs, we constructed TF-overexpression strains and analyzed lipid droplet (LD) formation and TAG contents in the cells grown under standard conditions. Based on the results, we identified four TFs involved in LD and TAG accumulation. RNA-Seq analyses were performed to identify genes regulated by the four TFs using each overexpression strain. Among the TAG biosynthesis-related genes, only the gene encoding the endoplasmic reticulum-localized lysophosphatidic acid acyltransferase 1 (LPAT1) was notably increased among the overexpression strains. In the LPAT1 overexpression strain, TAG accumulation was significantly increased compared with the control strain under normal growth conditions. These results indicate that the four TFs positively regulate TAG accumulation by changing their target gene expression in C. merolae.
Collapse
|
17
|
Ichinose TM, Iwane AH. Long-term live cell cycle imaging of single Cyanidioschyzon merolae cells. PROTOPLASMA 2021; 258:651-660. [PMID: 33580410 PMCID: PMC8052221 DOI: 10.1007/s00709-020-01592-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/24/2020] [Indexed: 05/26/2023]
Abstract
Live cell imaging by fluorescence microscopy is a useful tool for elucidating the localization and function of proteins and organelles in single cells. Especially, time-lapse analysis observing the same field sequentially can be used to observe cells of many organisms and analyze the dynamics of intracellular molecules. By single-cell analysis, it is possible to elucidate the characteristics and fluctuations of individual cells, which cannot be elucidated from the data obtained by averaging the characteristics of an ensemble of cells. The primitive red alga Cyanidioschyzon merolae has a very simple structure and is considered a useful model organism for studying the mechanism of organelle division, since the division is performed synchronously with the cell cycle. However, C. merolae does not have a rigid cell wall, and environmental changes such as low temperature or high pH cause morphological change and disruption easily. Therefore, morphological studies of C. merolae typically use fixed cells. In this study, we constructed a long-term time-lapse observation system to analyze the dynamics of proteins in living C. merolae cells. From the results, we elucidate the cell division process of single living cells, including the function of intracellular components.
Collapse
Affiliation(s)
- Takako M Ichinose
- Center for Biosystems Dynamics Research, Laboratory for Cell Field Structure, Riken, 3-10-23, Kagamiyama, Higashihiroshima, 739-0046, Japan
| | - Atsuko H Iwane
- Center for Biosystems Dynamics Research, Laboratory for Cell Field Structure, Riken, 3-10-23, Kagamiyama, Higashihiroshima, 739-0046, Japan.
- Graduate School of Frontier BioScience for Systems Science of Biological Dynamics, Osaka University, 1-3, Suita, 565-0871, Japan.
- Graduate School of Integrated Sciences for Life, Hiroshima University, 3-10-23, Kagamiyama, Higashihiroshima, 739-0046, Japan.
| |
Collapse
|
18
|
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.
Collapse
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
| |
Collapse
|
19
|
Hirooka S, Tomita R, Fujiwara T, Ohnuma M, Kuroiwa H, Kuroiwa T, Miyagishima SY. Efficient open cultivation of cyanidialean red algae in acidified seawater. Sci Rep 2020; 10:13794. [PMID: 32839467 PMCID: PMC7445282 DOI: 10.1038/s41598-020-70398-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 07/21/2020] [Indexed: 11/22/2022] Open
Abstract
Microalgae possess high potential for producing pigments, antioxidants, and lipophilic compounds for industrial applications. However, their open pond cultures are often contaminated by other undesirable organisms, including their predators. In addition, the cost of using freshwater is relatively high, which limits the location and scale of cultivation compared with using seawater. It was previously shown that Cyanidium caldarium and Galdieria sulphuraria, but not Cyanidioschyzon merolae grew in media containing NaCl at a concentration equivalent to seawater. We found that the preculture of C. merolae in the presence of a moderate NaCl concentration enabled the cells to grow in the seawater-based medium. The cultivation of cyanidialean red algae in the seawater-based medium did not require additional pH buffering chemicals. In addition, the combination of seawater and acidic conditions reduced the risk of contamination by other organisms in the nonsterile open culture of C. merolae more efficiently than the acidic condition alone.
Collapse
Affiliation(s)
- Shunsuke Hirooka
- Department of Gene Function and Phenomics, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.
| | - Reiko Tomita
- Department of Gene Function and Phenomics, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Takayuki Fujiwara
- Department of Gene Function and Phenomics, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.,Department of Genetics, Graduate University for Advanced Studies (SOKENDAI), 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Mio Ohnuma
- National Institute of Technology (KOSEN), Hiroshima College, 4272-1 Higashino, Osakikamijima, Toyota, Hiroshima, 725-0231, Japan
| | - Haruko Kuroiwa
- Department of Chemical and Biological Science, Faculty of Science, Japan Women's University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo, 112-8681, Japan
| | - Tsuneyoshi Kuroiwa
- Department of Chemical and Biological Science, Faculty of Science, Japan Women's University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo, 112-8681, Japan
| | - Shin-Ya Miyagishima
- Department of Gene Function and Phenomics, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan. .,Department of Genetics, Graduate University for Advanced Studies (SOKENDAI), 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.
| |
Collapse
|
20
|
Prevalent pH Controls the Capacity of Galdieria maxima to Use Ammonia and Nitrate as a Nitrogen Source. PLANTS 2020; 9:plants9020232. [PMID: 32054108 PMCID: PMC7076501 DOI: 10.3390/plants9020232] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/15/2020] [Accepted: 01/29/2020] [Indexed: 11/21/2022]
Abstract
Galdieria maxima is a polyextremophilic alga capable of diverse metabolic processes. Ammonia is widely used in culture media typical of laboratory growth. Recent reports that this species can grow on wastes promote the concept that G. maxima might have biotechnological utility. Accordingly, there is a need to know the range of pH levels that can support G. maxima growth in a given nitrogen source. Here, we examined the combined effect of pH and nitrate/ammonium source on the growth and long-term response of the photochemical process to a pH gradient in different G. maxima strains. All were able to use differing nitrogen sources, despite both the growth rate and photochemical activity were significantly affected by the combination with the pH. All strains acidified the NH4+-medium (pH < 3) except G. maxima IPPAS P507. Under nitrate at pH ≥ 6.5, no strain was able to acidify the medium; noteworthy, G. maxima ACUF551 showed a good growth performance under nitrate at pH 5, despite the alkalization of the medium.
Collapse
|
21
|
Liu X, Huan Z, Zhang Q, Zhong M, Chen W, Aslam M, Du H. Glutamine Synthetase (GS): A Key Enzyme for Nitrogen Assimilation in The Macroalga Gracilariopsis lemaneiformis (Rhodophyta). JOURNAL OF PHYCOLOGY 2019; 55:1059-1070. [PMID: 31206671 DOI: 10.1111/jpy.12891] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 05/17/2019] [Indexed: 05/21/2023]
Abstract
This study aimed to address the importance of glutamine synthetase II (GSII) during nitrogen assimilation in macroalga Gracilariopsis lemaneiformis. The cDNA full-length sequence of the three glGSII genes was revealed to have the 5' m7 G cap, 5'-untranslated region, open reading frame (ORF), 3'-untranslated region, and a 3' poly (A) tail. The three glGSIIs were classified into plastid glGS2 and cytosolic glGS1-1 and glGS1-2, having conserved GSII domains but different cDNA sequences. The complicated 5' end flanking region indicates complex function of glGS genes. glGS1 genes were significantly up-regulated under the different NH4+ : NO3- ratio (i.e., 40:10, 25:25, 10:40, and 0:50) except glGS2 which dramatically up-regulated under the low NH4+ : NO3- ratio (i.e., 10:40 and 0:50) during different cultivation times. These different expression patterns perhaps are due to the different biological roles of GS1 and GS2 in the gene family. Furthermore, hypothetical working model of nitrogen assimilation pathway exhibiting the role of glGS1 and glGS2 is proposed. Finally, glGS2 was expressed in Escherichia coli BL21 (DE3), and the optimal conditions for culture (15°C, overnight), purification (500 mM imidazole washing), and activity (pH 7.4, 37°C) were established. This study lays a very important foundation for exploring the role of GS in nitrogen assimilation in algae and plants.
Collapse
Affiliation(s)
- Xiaojuan Liu
- Guangdong Provincial Key Laboratory of Marine Biotechnology and STU-UNIVPM Joint Algal Research Center, College of Sciences, Shantou University, Shantou, 515063, China
| | - Zhongyan Huan
- Guangdong Provincial Key Laboratory of Marine Biotechnology and STU-UNIVPM Joint Algal Research Center, College of Sciences, Shantou University, Shantou, 515063, China
| | - Qingfang Zhang
- Guangdong Provincial Key Laboratory of Marine Biotechnology and STU-UNIVPM Joint Algal Research Center, College of Sciences, Shantou University, Shantou, 515063, China
| | - Mingqi Zhong
- Guangdong Provincial Key Laboratory of Marine Biotechnology and STU-UNIVPM Joint Algal Research Center, College of Sciences, Shantou University, Shantou, 515063, China
| | - Weizhou Chen
- Guangdong Provincial Key Laboratory of Marine Biotechnology and STU-UNIVPM Joint Algal Research Center, College of Sciences, Shantou University, Shantou, 515063, China
| | - Muhammad Aslam
- Guangdong Provincial Key Laboratory of Marine Biotechnology and STU-UNIVPM Joint Algal Research Center, College of Sciences, Shantou University, Shantou, 515063, China
| | - Hong Du
- Guangdong Provincial Key Laboratory of Marine Biotechnology and STU-UNIVPM Joint Algal Research Center, College of Sciences, Shantou University, Shantou, 515063, China
| |
Collapse
|
22
|
Zienkiewicz M, Krupnik T, Drożak A, Kania K. PEG-mediated, Stable, Nuclear and Chloroplast Transformation of Cyanidioschizon merolae. Bio Protoc 2019; 9:e3355. [PMID: 33654854 DOI: 10.21769/bioprotoc.3355] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 08/22/2019] [Accepted: 08/22/2019] [Indexed: 12/23/2022] Open
Abstract
The ability to achieve nuclear or chloroplast transformation in plants has been a long standing goal, especially in microalgae research. Over past years there has been only little success, but transient and stable nuclear transformation has been achieved in multiple species. Our newly developed method allows for relatively simple transformation of Cyanidioschizon merolae in both nuclear and chloroplast genome by means of homologous recombination between the genome and a transformation vector. The use of chloramphenicol resistance gene as the selectable marker allows for plate-based efficient selection of mutant colonies. Overall, the method allows the generation of mutant strains within 6 months.
Collapse
Affiliation(s)
| | - Tomasz Krupnik
- Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | - Anna Drożak
- Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| | - Kinga Kania
- Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland
| |
Collapse
|
23
|
Liu X, Wen J, Chen W, Du H. Physiological effects of nitrogen deficiency and recovery on the macroalga Gracilariopsis lemaneiformis (Rhodophyta). JOURNAL OF PHYCOLOGY 2019; 55:830-839. [PMID: 30916786 DOI: 10.1111/jpy.12862] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 03/05/2019] [Indexed: 05/07/2023]
Abstract
Algal metabolites are the most promising feedstocks for bio-energy production. Gracilariopsis lemaneiformis seems to be a good candidate red alga for polysaccharide production, especially relating to the agar production industry. Nitrogen deficiency is an efficient environmental pressure used to increase the accumulation of metabolites in algae. However, there are no studies on the physiological effects of G. lemaneiformis in response to nitrogen deficiency and its subsequent recovery. Here we integrated physiological data with molecular studies to explore the response strategy of G. lemaneiformis under nitrogen deficiency and recovery. Physiological measurements indicated that amino acids and protein biosynthesis were decreased, while endogenous NH4+ and soluble polysaccharides levels were increased under nitrogen stress. The expression of key genes involved in these pathways further suggested that G. lemaneiformis responded to nitrogen stress through up-regulation or down-regulation of genes related to nitrogen metabolism, and increased levels of endogenous NH4+ to complement the deficiency of exogenous nitrogen. Consistent with the highest accumulation of soluble polysaccharides, the gene encoding UDP-glucose pyrophosphorylase, a molecular marker used to evaluate agar content, was dramatically up-regulated more than 4-fold compared to the relative expression of actin after 4 d of nitrogen recovery. The present data provide important information on the mechanisms of nutrient balance in macroalgae.
Collapse
Affiliation(s)
- Xiaojuan Liu
- Guangdong Provincial Key Laboratory of Marine Biotechnology and STU-UNIVPM Joint Algal Research Center, College of Sciences, Shantou University, Shantou, Guangdong, 515063, China
| | - Jinyan Wen
- Guangdong Provincial Key Laboratory of Marine Biotechnology and STU-UNIVPM Joint Algal Research Center, College of Sciences, Shantou University, Shantou, Guangdong, 515063, China
| | - Weizhou Chen
- Guangdong Provincial Key Laboratory of Marine Biotechnology and STU-UNIVPM Joint Algal Research Center, College of Sciences, Shantou University, Shantou, Guangdong, 515063, China
| | - Hong Du
- Guangdong Provincial Key Laboratory of Marine Biotechnology and STU-UNIVPM Joint Algal Research Center, College of Sciences, Shantou University, Shantou, Guangdong, 515063, China
| |
Collapse
|
24
|
Moriyama T, Mori N, Nagata N, Sato N. Selective loss of photosystem I and formation of tubular thylakoids in heterotrophically grown red alga Cyanidioschyzon merolae. PHOTOSYNTHESIS RESEARCH 2019; 140:275-287. [PMID: 30415289 DOI: 10.1007/s11120-018-0603-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Accepted: 11/02/2018] [Indexed: 05/19/2023]
Abstract
We previously found that glycerol is required for heterotrophic growth in the unicellular red alga Cyanidioschyzon merolae. Here, we analyzed heterotrophically grown cells in more detail. Sugars or other organic substances did not support the growth in the dark. The growth rate was 0.4 divisions day-1 in the presence of 400 mM glycerol, in contrast with 0.5 divisions day-1 in the phototrophic growth. The growth continued until the sixth division. Unlimited heterotrophic growth was possible in the medium containing DCMU and glycerol in the light. Light-activated heterotrophic culture in which cells were irradiated by intermittent light also continued without an apparent limit. In the heterotrophic culture in the dark, chlorophyll content drastically decreased, as a result of inability of dark chlorophyll synthesis. Photosynthetic activity gradually decreased over 10 days, and finally lost after 19 days. Low-temperature fluorescence measurement and immunoblot analysis showed that this decline in photosynthetic activity was mainly due to the loss of Photosystem I, while the levels of Photosystem II and phycobilisomes were maintained. Accumulated triacylglycerol was lost during the heterotrophic growth, while keeping the overall lipid composition. Observation by transmission electron microscopy revealed that a part of thylakoid membranes turned into pentagonal tubular structures, on which five rows of phycobilisomes were aligned. This might be a structure that compactly conserve phycobilisomes and Photosystem II in an inactive state, probably as a stock of carbon and nitrogen. These results suggest that C. merolae has a unique strategy of heterotrophic growth, distinct from those found in other red algae.
Collapse
Affiliation(s)
- Takashi Moriyama
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902, Japan
| | - Natsumi Mori
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902, Japan
| | - Noriko Nagata
- Department of Chemical Biological Sciences, Faculty of Science, Japan Women's University, Mejirodai 2-8-1, Bunkyo-ku, Tokyo, 112-8681, Japan
| | - Naoki Sato
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902, Japan.
| |
Collapse
|
25
|
Pancha I, Tanaka K, Imamura S. Overexpression of a glycogenin, CmGLG2, enhances floridean starch accumulation in the red alga Cyanidioschyzon merolae. PLANT SIGNALING & BEHAVIOR 2019; 14:1596718. [PMID: 30938572 PMCID: PMC6546146 DOI: 10.1080/15592324.2019.1596718] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 03/10/2019] [Accepted: 03/12/2019] [Indexed: 06/09/2023]
Abstract
Microalgae accumulate energy-reserved molecules, such as triacylglycerol and carbohydrates, which are suitable feedstocks for renewable energies such as biodiesel and bioethanol. However, the molecular mechanisms behind the microalgae accumulating these molecules require further elucidation. Recently, we have reported that the target of rapamycin (TOR)-signaling is a major pathway to regulate floridean starch synthesis by changing the phosphorylation status of CmGLG1, a glycogenin generally required for the initiation of starch/glycogen synthesis, in the unicellular red alga Cyanidioschyzon merolae. In the present study, we confirmed that another glycogenin, CmGLG2, is also involved in the floridean starch synthesis in this alga, since the CmGLG2 overexpression resulted in a two-fold higher floridean starch content in the cell. The results indicate that both glycogenin isoforms play an important role in floridean starch synthesis in C. merolae, and would be a potential target for improvement of floridean starch production in microalgae.
Collapse
Affiliation(s)
- Imran Pancha
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
| |
Collapse
|
26
|
Fujiwara T, Hirooka S, Mukai M, Ohbayashi R, kanesaki Y, Watanabe S, Miyagishima S. Integration of a Galdieria plasma membrane sugar transporter enables heterotrophic growth of the obligate photoautotrophic red alga Cynanidioschyzon merolae. PLANT DIRECT 2019; 3:e00134. [PMID: 31245772 PMCID: PMC6589524 DOI: 10.1002/pld3.134] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 03/11/2019] [Accepted: 03/28/2019] [Indexed: 05/19/2023]
Abstract
The unicellular thermoacidophilic red alga Cyanidioschyzon merolae is an emerging model organism of photosynthetic eukaryotes. Its relatively simple genome (16.5 Mbp) with very low-genetic redundancy and its cellular structure possessing one chloroplast, mitochondrion, peroxisome, and other organelles have facilitated studies. In addition, this alga is genetically tractable, and the nuclear and chloroplast genomes can be modified by integration of transgenes via homologous recombination. Recent studies have attempted to clarify the structure and function of the photosystems of this alga. However, it is difficult to obtain photosynthesis-defective mutants for molecular genetic studies because this organism is an obligate autotroph. To overcome this issue in C. merolae, we expressed a plasma membrane sugar transporter, GsSPT1, from Galdieria sulphuraria, which is an evolutionary relative of C. merolae and capable of heterotrophic growth. The heterologously expressed GsSPT1 localized at the plasma membrane. GsSPT1 enabled C. merolae to grow mixotrophically and heterotrophically, in which cells grew in the dark with glucose or in the light with a photosynthetic inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and glucose. When the GsSPT1 transgene multiplied on the C. merolae chromosome via the URA Cm-Gs selection marker, which can multiply itself and its flanking transgene, GsSPT1 protein level increased and the heterotrophic and mixotrophic growth of the transformant accelerated. We also found that GsSPT1 overexpressing C. merolae efficiently formed colonies on solidified medium under light with glucose and DCMU. Thus, GsSPT1 overexpresser will facilitate single colony isolation and analyses of photosynthesis-deficient mutants produced either by random or site-directed mutagenesis. In addition, our results yielded evidence supporting that the presence or absence of plasma membrane sugar transporters is a major cause of difference in trophic properties between C. merolae and G. sulphuraria.
Collapse
Affiliation(s)
- Takayuki Fujiwara
- Department of Gene Function and PhenomicsNational Institute of GeneticsMishimaShizuokaJapan
- JST‐Mirai ProgramJapan Science and Technology AgencyKawaguchiSaitamaJapan
- Department of GeneticsGraduate University for Advanced Studies (SOKENDAI)MishimaShizuokaJapan
| | - Shunsuke Hirooka
- Department of Gene Function and PhenomicsNational Institute of GeneticsMishimaShizuokaJapan
- JST‐Mirai ProgramJapan Science and Technology AgencyKawaguchiSaitamaJapan
| | - Mizuna Mukai
- Department of BioscienceTokyo University of AgricultureTokyoJapan
| | - Ryudo Ohbayashi
- Department of Gene Function and PhenomicsNational Institute of GeneticsMishimaShizuokaJapan
| | - Yu kanesaki
- NODAI Genome Research CenterTokyoJapan
- Research Institute of Green Science and TechnologyShizuoka UniversityShizuokaJapan
| | - Satoru Watanabe
- Department of BioscienceTokyo University of AgricultureTokyoJapan
| | - Shin‐ya Miyagishima
- Department of Gene Function and PhenomicsNational Institute of GeneticsMishimaShizuokaJapan
- JST‐Mirai ProgramJapan Science and Technology AgencyKawaguchiSaitamaJapan
- Department of GeneticsGraduate University for Advanced Studies (SOKENDAI)MishimaShizuokaJapan
| |
Collapse
|
27
|
Ocaña-Pallarès E, Najle SR, Scazzocchio C, Ruiz-Trillo I. Reticulate evolution in eukaryotes: Origin and evolution of the nitrate assimilation pathway. PLoS Genet 2019; 15:e1007986. [PMID: 30789903 PMCID: PMC6400420 DOI: 10.1371/journal.pgen.1007986] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 03/05/2019] [Accepted: 01/25/2019] [Indexed: 01/17/2023] Open
Abstract
Genes and genomes can evolve through interchanging genetic material, this leading to reticular evolutionary patterns. However, the importance of reticulate evolution in eukaryotes, and in particular of horizontal gene transfer (HGT), remains controversial. Given that metabolic pathways with taxonomically-patchy distributions can be indicative of HGT events, the eukaryotic nitrate assimilation pathway is an ideal object of investigation, as previous results revealed a patchy distribution and suggested that the nitrate assimilation cluster of dikaryotic fungi (Opisthokonta) could have been originated and transferred from a lineage leading to Oomycota (Stramenopiles). We studied the origin and evolution of this pathway through both multi-scale bioinformatic and experimental approaches. Our taxon-rich genomic screening shows that nitrate assimilation is present in more lineages than previously reported, although being restricted to autotrophs and osmotrophs. The phylogenies indicate a pervasive role of HGT, with three bacterial transfers contributing to the pathway origin, and at least seven well-supported transfers between eukaryotes. In particular, we propose a distinct and more complex HGT path between Opisthokonta and Stramenopiles than the one previously suggested, involving at least two transfers of a nitrate assimilation gene cluster. We also found that gene fusion played an essential role in this evolutionary history, underlying the origin of the canonical eukaryotic nitrate reductase, and of a chimeric nitrate reductase in Ichthyosporea (Opisthokonta). We show that the ichthyosporean pathway, including this novel nitrate reductase, is physiologically active and transcriptionally co-regulated, responding to different nitrogen sources; similarly to distant eukaryotes with independent HGT-acquisitions of the pathway. This indicates that this pattern of transcriptional control evolved convergently in eukaryotes, favoring the proper integration of the pathway in the metabolic landscape. Our results highlight the importance of reticulate evolution in eukaryotes, by showing the crucial contribution of HGT and gene fusion in the evolutionary history of the nitrate assimilation pathway. One of the most relevant findings in evolution was that lineages, either genes or genomes, can evolve through interchanging genetic material. For example, exon shuffling can lead to genes with complete novel functions, and genomes can acquire novel functionalities by means of horizontal gene transfer (HGT). Whereas HGT is known to be an important driver of metabolic remodelling and ecological adaptations in Bacteria, its importance and prevalence in eukaryotes remains controversial. We show that HGT played a major role in the origin and evolution of the eukaryotic nitrate assimilation pathway, with several bacteria-to-eukaryote and eukaryote-to-eukaryote transfers promoting the acquisition of this ecologically-relevant pathway to autotrophs and to distinct groups of osmotrophs. Moreover, we also show that gene fusion was important in this evolutionary history, underlying the origin of the canonical eukaryotic nitrate reductase, but also of a non-canonical nitrate reductase that we describe in Ichthyosporea, a poorly-characterized eukaryotic group that includes many parasitic species. In conclusion, our results highlight the importance of reticulate evolution in eukaryotes, by showing the contribution of HGT and gene fusion in the evolutionary history of the nitrate assimilation pathway.
Collapse
Affiliation(s)
- Eduard Ocaña-Pallarès
- Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Barcelona, Catalonia, Spain
- * E-mail: (EOP); (IRT)
| | - Sebastián R. Najle
- Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Barcelona, Catalonia, Spain
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda s/n, Rosario S2000FHQ, Argentina
| | - Claudio Scazzocchio
- Department of Microbiology, Imperial College, London, United Kingdom
- Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Iñaki Ruiz-Trillo
- Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Barcelona, Catalonia, Spain
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona (UB), Barcelona, Catalonia, Spain
- ICREA, Barcelona, Catalonia, Spain
- * E-mail: (EOP); (IRT)
| |
Collapse
|
28
|
Takemura T, Kobayashi Y, Imamura S, Tanaka K. Top Starch Plating Method for the Efficient Cultivation of Unicellular Red Alga Cyanidioschyzon merolae. Bio Protoc 2019; 9:e3172. [PMID: 33654978 PMCID: PMC7854263 DOI: 10.21769/bioprotoc.3172] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 01/23/2019] [Accepted: 01/24/2019] [Indexed: 12/25/2022] Open
Abstract
The unicellular red alga Cyanidioschyzon merolae has been used as a model photosynthetic eukaryote for various basic and applied studies, and several of these molecular genetics techniques have been reported. However, there are still improvements to be made concerning the plating method. The conventional plating method often generates diffuse colonies and single colonies cannot be easily isolated. To overcome these problems, we established a novel plating method for C. merolae, making use of melted cornstarch as the use of top agar plating in bacterial genetics. This method improved the formation of defined colonies in at least 4-fold higher efficiency than the conventional method, and made the handling procedure much easier than the previous method.
Collapse
Affiliation(s)
- Tokiaki Takemura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta 4259-R1-29, Yokohama 226-8503, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta 4259-R1-29, Yokohama 226-8503, Japan
| | - Yuki Kobayashi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta 4259-R1-29, Yokohama 226-8503, Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta 4259-R1-29, Yokohama 226-8503, Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta 4259-R1-29, Yokohama 226-8503, Japan
| |
Collapse
|
29
|
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: 3.8] [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.
Collapse
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
| |
Collapse
|
30
|
Expression of novel nitrate reductase genes in the harmful alga, Chattonella subsalsa. Sci Rep 2018; 8:13417. [PMID: 30194416 PMCID: PMC6128913 DOI: 10.1038/s41598-018-31735-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 08/23/2018] [Indexed: 12/20/2022] Open
Abstract
Eukaryotic nitrate reductase (NR) catalyzes the first step in nitrate assimilation and is regulated transcriptionally in response to external cues and intracellular metabolic status. NRs are also regulated post-translationally in plants by phosphorylation and binding of 14-3-3 proteins at conserved serine residues. 14-3-3 binding motifs have not previously been identified in algal NRs. A novel NR (NR2-2/2HbN) with a 2/2 hemoglobin domain was recently described in the alga Chattonella subsalsa. Here, a second NR (NR3) in C. subsalsa is described with a 14-3-3 binding motif but lacking the Heme-Fe domain found in other NRs. Transcriptional regulation of both NRs was examined in C. subsalsa, revealing differential gene expression over a diel light cycle, but not under constant light. NR2 transcripts increased with a decrease in temperature, while NR3 remained unchanged. NR2 and NR3 transcript levels were not inhibited by growth on ammonium, suggesting constitutive expression of these genes. Results indicate that Chattonella responds to environmental conditions and intracellular metabolic status by differentially regulating NR transcription, with potential for post-translational regulation of NR3. A survey of algal NRs also revealed the presence of 14-3-3 binding motifs in other algal species, indicating the need for future research on regulation of algal NRs.
Collapse
|
31
|
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: 4.7] [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.
Collapse
|
32
|
Imamura S, Nomura Y, Takemura T, Pancha I, Taki K, Toguchi K, Tozawa Y, Tanaka K. The checkpoint kinase TOR (target of rapamycin) regulates expression of a nuclear-encoded chloroplast RelA-SpoT homolog (RSH) and modulates chloroplast ribosomal RNA synthesis in a unicellular red alga. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 94:327-339. [PMID: 29441718 DOI: 10.1111/tpj.13859] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 12/11/2017] [Accepted: 01/23/2018] [Indexed: 05/14/2023]
Abstract
Chloroplasts are plant organelles that carry out oxygenic photosynthesis. Chloroplast biogenesis depends upon chloroplast ribosomes and their translational activity. However, regulation of chloroplast ribosome biogenesis remains an important unanswered question. In this study, we found that inhibition of target of rapamycin (TOR), a general eukaryotic checkpoint kinase, results in a decline in chloroplast ribosomal RNA (rRNA) transcription in the unicellular red alga, Cyanidioschyzon merolae. Upon TOR inhibition, transcriptomics and other analyses revealed increased expression of a nuclear-encoded chloroplast RelA-SpoT homolog (RSH) gene (CmRSH4b), which encodes a homolog of the guanosine 3'-diphosphate 5'-diphosphate (ppGpp) synthetases that modulate rRNA synthesis in bacteria. Using an Escherichia coli mutant lacking ppGpp, CmRSH4b was demonstrated to have ppGpp synthetase activity. Expression analysis of a green fluorescent protein-fused protein indicated that CmRSH4b localizes to the chloroplast, and overexpression of the CmRSH4b gene resulted in a decrease of chloroplast rRNA synthesis concomitant with growth inhibition and reduction of chloroplast size. Biochemical analyses using C. merolae cell lysates or purified recombinant proteins revealed that ppGpp inhibits bacteria-type RNA polymerase-dependent chloroplast rRNA synthesis as well as a chloroplast guanylate kinase. These results suggest that CmRSH4b-dependent ppGpp synthesis in chloroplasts is an important regulator of chloroplast rRNA transcription. Nuclear and mitochondrial rRNA transcription were both reduced by TOR inhibition, suggesting that the biogeneses of the three independent ribosome systems are interconnected by TOR in plant cells.
Collapse
Affiliation(s)
- 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
| | - Yuhta Nomura
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan
| | - Tokiaki Takemura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - 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
| | - Keiko Taki
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Kazuki Toguchi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Yuzuru Tozawa
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, 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
| |
Collapse
|
33
|
Sabu S, Singh ISB, Joseph V. Optimisation of critical medium components and culture conditions for enhanced biomass and lipid production in the oleaginous diatom Navicula phyllepta: a statistical approach. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:26763-26777. [PMID: 28963632 DOI: 10.1007/s11356-017-0274-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 09/19/2017] [Indexed: 06/07/2023]
Abstract
Diatoms hold great promise as potential sources of biofuel production. In the present study, the biomass and lipid production in the marine diatom Navicula phyllepta, isolated from Cochin estuary, India and identified as a potential biodiesel feedstock, were optimized using Plackett-Burman (PB) statistical experimental design followed by central composite design (CCD) and response surface methodology (RSM). The growth analyses of the isolate in different nitrogen sources, salinities and five different enriched sea water media showed the best growth in the cheapest medium with minimum components using urea as nitrogen source at salinity between 25 and 40 g kg-1. Plackett-Burman experimental analyses for screening urea, sodium metasilicate, sodium dihydrogen phosphate, ferric chloride, salinity, temperature, pH and agitation influencing lipid and biomass production showed that silicate and temperature had a positive coefficient on biomass production, and temperature had a significant positive coefficient, while urea and phosphate showed a negative coefficient on lipid content. A 24 factorial central composite design (FCCD) was used to optimize the concentration of the factors selected. The optimized media resulted in 1.62-fold increase (64%) in biomass (1.2 ± 0.08 g L-1) and 1.2-fold increase (22%) in estimated total lipid production (0.11 ± 0.003 g L-1) compared to original media within 12 days of culturing. A significantly higher biomass and lipid production in the optimized medium demands further development of a two-stage strategy of biomass production followed by induction of high lipid production under nutrient limitation or varying culture conditions for large-scale production of biodiesel from the marine diatom.
Collapse
Affiliation(s)
- Sanyo Sabu
- National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Kochi, Kerala, 682016, India
| | - Isaac Sarojini Bright Singh
- National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Kochi, Kerala, 682016, India
| | - Valsamma Joseph
- National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Kochi, Kerala, 682016, India.
| |
Collapse
|
34
|
Rademacher N, Wrobel TJ, Rossoni AW, Kurz S, Bräutigam A, Weber APM, Eisenhut M. Transcriptional response of the extremophile red alga Cyanidioschyzon merolae to changes in CO 2 concentrations. JOURNAL OF PLANT PHYSIOLOGY 2017; 217:49-56. [PMID: 28705662 DOI: 10.1016/j.jplph.2017.06.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 06/20/2017] [Accepted: 06/22/2017] [Indexed: 05/19/2023]
Abstract
Cyanidioschyzon merolae (C. merolae) is an acidophilic red alga growing in a naturally low carbon dioxide (CO2) environment. Although it uses a ribulose 1,5-bisphosphate carboxylase/oxygenase with high affinity for CO2, the survival of C. merolae relies on functional photorespiratory metabolism. In this study, we quantified the transcriptomic response of C. merolae to changes in CO2 conditions. We found distinct changes upon shifts between CO2 conditions, such as a concerted up-regulation of photorespiratory genes and responses to carbon starvation. We used the transcriptome data set to explore a hypothetical CO2 concentrating mechanism in C. merolae, based on the assumption that photorespiratory genes and possible candidate genes involved in a CO2 concentrating mechanism are co-expressed. A putative bicarbonate transport protein and two α-carbonic anhydrases were identified, which showed enhanced transcript levels under reduced CO2 conditions. Genes encoding enzymes of a PEPCK-type C4 pathway were co-regulated with the photorespiratory gene cluster. We propose a model of a hypothetical low CO2 compensation mechanism in C. merolae integrating these low CO2-inducible components.
Collapse
Affiliation(s)
- Nadine Rademacher
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Thomas J Wrobel
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Alessandro W Rossoni
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Samantha Kurz
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Andrea Bräutigam
- Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung (IPK), Corrensstraße 3, 06466 Stadt Seeland, OT Gatersleben, Germany
| | - Andreas P M Weber
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Marion Eisenhut
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Universitätsstraße 1, 40225 Düsseldorf, Germany.
| |
Collapse
|
35
|
Imamura S, Taki K, Tanaka K. Construction of a rapamycin-susceptible strain of the unicellular red alga Cyanidioschyzon merolae for analysis of the target of rapamycin (TOR) function. J GEN APPL MICROBIOL 2017; 63:305-309. [PMID: 28954966 DOI: 10.2323/jgam.2017.02.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology.,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST)
| | - Keiko Taki
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology.,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST)
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology.,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST)
| |
Collapse
|
36
|
Kawase Y, Imamura S, Tanaka K. A MYB-type transcription factor, MYB2, represses light-harvesting protein genes in Cyanidioschyzon merolae. FEBS Lett 2017; 591:2439-2448. [PMID: 28748638 DOI: 10.1002/1873-3468.12763] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 07/18/2017] [Accepted: 07/19/2017] [Indexed: 11/07/2022]
Abstract
While searching for transcriptional regulators that respond to changes in light regimes, we identified a MYB domain-containing protein, MYB2, that accumulates under dark and other conditions in the unicellular red alga Cyanidioschyzon merolae. The isolation and analysis of a MYB2 mutant revealed that MYB2 represses the expression of the nuclear-encoded chloroplast RNA polymerase sigma factor gene SIG2, which results in the repression of the chloroplast-encoded phycobilisome genes that are under its control. Since nuclear-encoded phycobilisome and other light-harvesting protein genes are also repressed by MYB2, we conclude that MYB2 has a role in repressing the expression of light-harvesting genes. The MYB2 mutant is sensitive to a prolonged dark incubation, indicating the importance of MYB2 for cell viability in the dark.
Collapse
Affiliation(s)
- Yasuko Kawase
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan.,Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yokohama, Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| |
Collapse
|
37
|
Yamaguchi S, Kawada Y, Yuge H, Tanaka K, Imamura S. Development of New Carbon Resources: Production of Important Chemicals from Algal Residue. Sci Rep 2017; 7:855. [PMID: 28405002 PMCID: PMC5429806 DOI: 10.1038/s41598-017-00979-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 03/17/2017] [Indexed: 12/19/2022] Open
Abstract
Algal biomass has received attention as an alternative carbon resource owing not only to its high oil production efficiency but also, unlike corn starch, to its lack of demand in foods. However, algal residue is commonly discarded after the abstraction of oil. The utilization of the residue to produce chemicals will therefore increase the value of using algal biomass instead of fossil fuels. Here, we report the use of algal residue as a new carbon resource to produce important chemicals. The application of different homogeneous catalysts leads to the selective production of methyl levulinate or methyl lactate. These results demonstrate the successful development of new carbon resources as a solution for the depletion of fossil fuels.
Collapse
Affiliation(s)
- Sho Yamaguchi
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 4259-G1-14 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8502, Japan.
| | - Yuuki Kawada
- Department of Chemistry, School of Science, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan
| | - Hidetaka Yuge
- Department of Chemistry, School of Science, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1-30 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8502, Japan.,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama, 332-0012, Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1-30 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8502, Japan.,Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama, 332-0012, Japan
| |
Collapse
|
38
|
Fujiwara T, Ohnuma M, Kuroiwa T, Ohbayashi R, Hirooka S, Miyagishima SY. Development of a Double Nuclear Gene-Targeting Method by Two-Step Transformation Based on a Newly Established Chloramphenicol-Selection System in the Red Alga Cyanidioschyzon merolae. FRONTIERS IN PLANT SCIENCE 2017; 8:343. [PMID: 28352279 PMCID: PMC5348525 DOI: 10.3389/fpls.2017.00343] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 02/27/2017] [Indexed: 05/24/2023]
Abstract
The unicellular red alga Cyanidioschyzon merolae possesses a simple cellular architecture that consists of one mitochondrion, one chloroplast, one peroxisome, one Golgi apparatus, and several lysosomes. The nuclear genome content is also simple, with very little genetic redundancy (16.5 Mbp, 4,775 genes). In addition, molecular genetic tools such as gene targeting and inducible gene expression systems have been recently developed. These cytological features and genetic tractability have facilitated various omics analyses. However, only a single transformation selection marker URA has been made available and thus the application of genetic modification has been limited. Here, we report the development of a nuclear targeting method by using chloramphenicol and the chloramphenicol acetyltransferase (CAT) gene. In addition, we found that at least 200-bp homologous arms are required and 500-bp arms are sufficient for a targeted single-copy insertion of the CAT selection marker into the nuclear genome. By means of a combination of the URA and CAT transformation systems, we succeeded in producing a C. merolae strain that expresses HA-cyclin 1 and FLAG-CDKA from the chromosomal CYC1 and CDKA loci, respectively. These methods of multiple nuclear targeting will facilitate genetic manipulation of C. merolae.
Collapse
Affiliation(s)
- Takayuki Fujiwara
- Department of Cell Genetics, National Institute of GeneticsShizuoka, Japan
- Japan Science and Technology Agency, Core Research for Evolutional Science and TechnologySaitama, Japan
- Department of Genetics, Graduate University for Advanced StudiesShizuoka, Japan
| | - Mio Ohnuma
- Japan Science and Technology Agency, Core Research for Evolutional Science and TechnologySaitama, Japan
- National Institute of Technology, Hiroshima CollegeHiroshima, Japan
| | - Tsuneyoshi Kuroiwa
- Japan Science and Technology Agency, Core Research for Evolutional Science and TechnologySaitama, Japan
- Department of Chemical and Biological Science, Faculty of Science, Japan Women’s UniversityTokyo, Japan
| | - Ryudo Ohbayashi
- Department of Cell Genetics, National Institute of GeneticsShizuoka, Japan
- Japan Science and Technology Agency, Core Research for Evolutional Science and TechnologySaitama, Japan
| | - Shunsuke Hirooka
- Department of Cell Genetics, National Institute of GeneticsShizuoka, Japan
- Japan Science and Technology Agency, Core Research for Evolutional Science and TechnologySaitama, Japan
| | - Shin-Ya Miyagishima
- Department of Cell Genetics, National Institute of GeneticsShizuoka, Japan
- Japan Science and Technology Agency, Core Research for Evolutional Science and TechnologySaitama, Japan
- Department of Genetics, Graduate University for Advanced StudiesShizuoka, Japan
| |
Collapse
|
39
|
Zienkiewicz M, Krupnik T, Drożak A, Golke A, Romanowska E. Chloramphenicol acetyltransferase-a new selectable marker in stable nuclear transformation of the red alga Cyanidioschyzon merolae. PROTOPLASMA 2017; 254:587-596. [PMID: 26715590 DOI: 10.1007/s00709-015-0936-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 12/21/2015] [Indexed: 05/03/2023]
Abstract
In this study, we have shown the applicability of chloramphenicol acetyltransferase as a new and convenient selectable marker for stable nuclear transformation as well as potential chloroplast transformation of Cyanidioschyzon merolae-a new model organism, which offers unique opportunities for studding the mitochondrial and plastid physiology as well as various evolutionary, structural, and functional features of the photosynthetic apparatus.
Collapse
|
40
|
Zienkiewicz M, Krupnik T, Drożak A, Golke A, Romanowska E. Transformation of the Cyanidioschyzon merolae chloroplast genome: prospects for understanding chloroplast function in extreme environments. PLANT MOLECULAR BIOLOGY 2017; 93:171-183. [PMID: 27796719 PMCID: PMC5243890 DOI: 10.1007/s11103-016-0554-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/22/2016] [Indexed: 05/06/2023]
Abstract
We have successfully transformed an exthemophilic red alga with the chloramphenicol acetyltransferase gene, rendering this organism insensitive to its toxicity. Our work paves the way to further work with this new modelorganism. Here we report the first successful attempt to achieve a stable, under selectable pressure, chloroplast transformation in Cyanidioschizon merolae-an extremophilic red alga of increasing importance as a new model organism. The following protocol takes advantage of a double homologous recombination phenomenon in the chloroplast, allowing to introduce an exogenous, selectable gene. For that purpose, we decided to use chloramphenicol acetyltransferase (CAT), as chloroplasts are particularly vulnerable to chloramphenicol lethal effects (Zienkiewicz et al. in Protoplasma, 2015, doi: 10.1007/s00709-015-0936-9 ). We adjusted two methods of DNA delivery: the PEG-mediated delivery and the biolistic bombardment based delivery, either of these methods work sufficiently with noticeable preference to the former. Application of a codon-optimized sequence of the cat gene and a single colony selection yielded C. merolae strains, capable of resisting up to 400 µg/mL of chloramphenicol. Our method opens new possibilities in production of site-directed mutants, recombinant proteins and exogenous protein overexpression in C. merolae-a new model organism.
Collapse
Affiliation(s)
- Maksymilian Zienkiewicz
- Department of Molecular Plant Physiology, Faculty of Biology, University of Warsaw, ul. Miecznikowa 1, 02-096, Warsaw, Poland.
| | - Tomasz Krupnik
- Department of Molecular Plant Physiology, Faculty of Biology, University of Warsaw, ul. Miecznikowa 1, 02-096, Warsaw, Poland
| | - Anna Drożak
- Department of Molecular Plant Physiology, Faculty of Biology, University of Warsaw, ul. Miecznikowa 1, 02-096, Warsaw, Poland
| | - Anna Golke
- Department of Molecular Plant Physiology, Faculty of Biology, University of Warsaw, ul. Miecznikowa 1, 02-096, Warsaw, Poland
| | - Elżbieta Romanowska
- Department of Molecular Plant Physiology, Faculty of Biology, University of Warsaw, ul. Miecznikowa 1, 02-096, Warsaw, Poland
| |
Collapse
|
41
|
Hirooka S, Miyagishima SY. Cultivation of Acidophilic Algae Galdieria sulphuraria and Pseudochlorella sp. YKT1 in Media Derived from Acidic Hot Springs. Front Microbiol 2016; 7:2022. [PMID: 28066348 PMCID: PMC5167705 DOI: 10.3389/fmicb.2016.02022] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 12/02/2016] [Indexed: 12/03/2022] Open
Abstract
Microalgae possess a high potential for producing pigments, antioxidants, and lipophilic compounds for industrial applications. However, the cultivation of microalgae comes at a high cost. To reduce the cost, changes from a closed bioreactor to open pond system and from a synthetic medium to environmental or wastewater-based medium are being sought. However, the use of open pond systems is currently limited because of contamination by undesirable organisms. To overcome this issue, one strategy is to combine acidophilic algae and acidic drainage in which other organisms are unable to thrive. Here, we tested waters from sulfuric acidic hot springs (Tamagawa, pH 1.15 and Tsukahara, pH 1.14) in Japan for the cultivation of the red alga Galdieria sulphuraria 074G and the green alga Pseudochlorella sp. YKT1. Both of these spring waters are rich in phosphate (0.043 and 0.145 mM, respectively) compared to other environmental freshwater sources. Neither alga grew in the spring water but they grew very well when the waters were supplemented with an inorganic nitrogen source. The algal yields were ∼2.73 g dry weight/L for G. sulphuraria and ∼2.49 g dry weight/L for P. sp. YKT1, which were comparable to those in an autotrophic synthetic medium. P. sp. YKT1 grew in the spring waters supplemented either of NH4+, NO3- or urea, while G. sulphuraria grew only when NH4+ was supplemented. For P. sp. YKT1, the spring water was adjusted to pH 2.0, while for G. sulphuraria, no pH adjustment was required. In both cases, no additional pH-buffering compound was required. The phycocyanin of the thermophilic G. sulphuraria is known to be more thermostable than that from the Spirulina platensis currently used in phycocyanin production for commercial use. The phycocyanin content in G. sulphuraria in the Tsukahara water supplemented with NH4+ was 107.42 ± 1.81 μg/mg dry weight, which is comparable to the level in S. platensis (148.3 μg/mg dry weight). P. sp. YKT1 cells in the Tamagawa water supplemented with a nitrogen source formed a large amount of lipid droplets while maintaining cellular growth. These results indicate the potential of sulfuric hot spring waters for large-scale algal cultivation at a low cost.
Collapse
Affiliation(s)
- Shunsuke Hirooka
- Department of Cell Genetics, National Institute of GeneticsMishima, Japan; Japan Science and Technology Agency, Core Research for Evolutionary Science and TechnologyKawaguchi, Japan
| | - Shin-Ya Miyagishima
- Department of Cell Genetics, National Institute of GeneticsMishima, Japan; Japan Science and Technology Agency, Core Research for Evolutionary Science and TechnologyKawaguchi, Japan; Department of Genetics, Graduate University for Advanced StudiesMishima, Japan
| |
Collapse
|
42
|
Rademacher N, Kern R, Fujiwara T, Mettler-Altmann T, Miyagishima SY, Hagemann M, Eisenhut M, Weber APM. Photorespiratory glycolate oxidase is essential for the survival of the red alga Cyanidioschyzon merolae under ambient CO2 conditions. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:3165-75. [PMID: 26994474 PMCID: PMC4867895 DOI: 10.1093/jxb/erw118] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Photorespiration is essential for all organisms performing oxygenic photosynthesis. The evolution of photorespiratory metabolism began among cyanobacteria and led to a highly compartmented pathway in plants. A molecular understanding of photorespiration in eukaryotic algae, such as glaucophytes, rhodophytes, and chlorophytes, is essential to unravel the evolution of this pathway. However, mechanistic detail of the photorespiratory pathway in red algae is scarce. The unicellular red alga Cyanidioschyzon merolae represents a model for the red lineage. Its genome is fully sequenced, and tools for targeted gene engineering are available. To study the function and importance of photorespiration in red algae, we chose glycolate oxidase (GOX) as the target. GOX catalyses the conversion of glycolate into glyoxylate, while hydrogen peroxide is generated as a side-product. The function of the candidate GOX from C. merolae was verified by the fact that recombinant GOX preferred glycolate over L-lactate as a substrate. Yellow fluorescent protein-GOX fusion proteins showed that GOX is targeted to peroxisomes in C. merolae The GOX knockout mutant lines showed a high-carbon-requiring phenotype with decreased growth and reduced photosynthetic activity compared to the wild type under ambient air conditions. Metabolite analyses revealed glycolate and glycine accumulation in the mutant cells after a shift from high CO2 conditions to ambient air. In summary, or results demonstrate that photorespiratory metabolism is essential for red algae. The use of a peroxisomal GOX points to a high photorespiratory flux as an ancestral feature of all photosynthetic eukaryotes.
Collapse
Affiliation(s)
- Nadine Rademacher
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Ramona Kern
- University Rostock, Department Plant Physiology, Albert-Einstein-Straße 3, 18059 Rostock, Germany
| | - Takayuki Fujiwara
- Division of Symbiosis and Cell Evolution, National Institute of Genetics, 1111 Yata, Mishima 411-8540, Shizuoka, Japan
| | - Tabea Mettler-Altmann
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Shin-Ya Miyagishima
- Division of Symbiosis and Cell Evolution, National Institute of Genetics, 1111 Yata, Mishima 411-8540, Shizuoka, Japan Japan Science and Technology Agency, CREST, 4-1-8 Honcho, Kawaguchi 332-0012, Saitama, Japan
| | - Martin Hagemann
- University Rostock, Department Plant Physiology, Albert-Einstein-Straße 3, 18059 Rostock, Germany
| | - Marion Eisenhut
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Andreas P M Weber
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Universitätsstraße 1, 40225 Düsseldorf, Germany
| |
Collapse
|
43
|
Nath M, Tuteja N. NPKS uptake, sensing, and signaling and miRNAs in plant nutrient stress. PROTOPLASMA 2016; 253:767-786. [PMID: 26085375 DOI: 10.1007/s00709-015-0845-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 06/08/2015] [Indexed: 05/24/2023]
Abstract
Sessile nature of higher plants consequently makes it highly adaptable for nutrient absorption and acquisition from soil. Plants require 17 essential elements for their growth and development which include 14 minerals (macronutrients: N, P, K, Mg, Ca, S; micronutrients: Cl, Fe, B, Mn, Zn, Cu, Ni, Mo) and 3 non-mineral (C, H, O) elements. The roots of higher plants must acquire these macronutrients and micronutrients from rhizosphere and further allocate to other plant parts for completing their life cycle. Plants evolved an intricate series of signaling and sensing cascades to maintain nutrient homeostasis and to cope with nutrient stress/availability. The specific receptors for nutrients in root, root system architecture, and internal signaling pathways help to develop plasticity in response to the nutrient starvation. Nitrogen (N), phosphorus (P), potassium (K), and sulfur (S) are essential for various metabolic processes, and their deficiency negatively effects the plant growth and yield. Genes coding for transporters and receptors for nutrients as well as some small non-coding RNAs have been implicated in nutrient uptake and signaling. This review summarizes the N, P, K, and S uptake, sensing and signaling events in nutrient stress condition especially in model plant Arabidopsis thaliana and involvement of microRNAs in nutrient deficiency. This article also provides a framework of uptake, sensing, signaling and to highlight the microRNA as an emerging major players in nutrient stress condition. Nutrient-plant-miRNA cross talk may help plant to cope up nutrient stress, and understanding their precise mechanism(s) will be necessary to develop high yielding smart crop with low nutrient input.
Collapse
Affiliation(s)
- Manoj Nath
- Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, 110067, New Delhi, India
| | - Narendra Tuteja
- Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, 110067, New Delhi, India.
| |
Collapse
|
44
|
Toyoshima M, Mori N, Moriyama T, Misumi O, Sato N. Analysis of triacylglycerol accumulation under nitrogen deprivation in the red alga Cyanidioschyzon merolae. MICROBIOLOGY-SGM 2016; 162:803-812. [PMID: 26925574 DOI: 10.1099/mic.0.000261] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Triacylglycerol (TAG) produced by microalgae is a potential source of biofuel. Although various metabolic pathways in TAG synthesis have been identified in land plants, the pathway of TAG synthesis in microalgae remains to be clarified. The unicellular rhodophyte Cyanidioschyzon merolae has unique properties as a producer of biofuel because of easy culture and feasibility of genetic engineering. Additionally, it is useful in the investigation of the pathway of TAG synthesis, because all of the nuclear, mitochondrial and plastid genomes have been completely sequenced. We found that this alga accumulated TAG under nitrogen deprivation. Curiously, the amount and composition of plastid membrane lipids did not change significantly, whereas the amount of endoplasmic reticulum (ER) lipids increased with considerable changes in fatty acid composition. The nitrogen deprivation did not decrease photosynthetic oxygen evolution per chlorophyll significantly, while phycobilisomes were degraded preferentially. These results suggest that the synthesis of fatty acids is maintained in the plastid, which is used for the synthesis of TAG in the ER. The accumulated TAG contained mainly 18 : 2(9,12) at the C-2 position, which could be derived from phosphatidylcholine, which also contains this acid at the C-2 position.
Collapse
Affiliation(s)
- Masakazu Toyoshima
- Department of Life Sciences, Graduate School of Arts and Science, The University of Tokyo,Tokyo,Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency,Tokyo,Japan
| | - Natsumi Mori
- Department of Life Sciences, Graduate School of Arts and Science, The University of Tokyo,Tokyo,Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency,Tokyo,Japan
| | - Takashi Moriyama
- Department of Life Sciences, Graduate School of Arts and Science, The University of Tokyo,Tokyo,Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency,Tokyo,Japan
| | - Osami Misumi
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency,Tokyo,Japan
- Department of Biological Science and Chemistry, Faculty of Science, Graduate School of Medicine, Yamaguchi University,Yamaguchi,Japan
| | - Naoki Sato
- Department of Life Sciences, Graduate School of Arts and Science, The University of Tokyo,Tokyo,Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency,Tokyo,Japan
| |
Collapse
|
45
|
Sanz-Luque E, Chamizo-Ampudia A, Llamas A, Galvan A, Fernandez E. Understanding nitrate assimilation and its regulation in microalgae. FRONTIERS IN PLANT SCIENCE 2015; 6:899. [PMID: 26579149 PMCID: PMC4620153 DOI: 10.3389/fpls.2015.00899] [Citation(s) in RCA: 176] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/09/2015] [Indexed: 05/02/2023]
Abstract
Nitrate assimilation is a key process for nitrogen (N) acquisition in green microalgae. Among Chlorophyte algae, Chlamydomonas reinhardtii has resulted to be a good model system to unravel important facts of this process, and has provided important insights for agriculturally relevant plants. In this work, the recent findings on nitrate transport, nitrate reduction and the regulation of nitrate assimilation are presented in this and several other algae. Latest data have shown nitric oxide (NO) as an important signal molecule in the transcriptional and posttranslational regulation of nitrate reductase and inorganic N transport. Participation of regulatory genes and proteins in positive and negative signaling of the pathway and the mechanisms involved in the regulation of nitrate assimilation, as well as those involved in Molybdenum cofactor synthesis required to nitrate assimilation, are critically reviewed.
Collapse
Affiliation(s)
| | | | | | | | - Emilio Fernandez
- Department of Biochemistry and Molecular Biology, University of CordobaCordoba, Spain
| |
Collapse
|
46
|
Imamura S, Kawase Y, Kobayashi I, Sone T, Era A, Miyagishima SY, Shimojima M, Ohta H, Tanaka K. Target of rapamycin (TOR) plays a critical role in triacylglycerol accumulation in microalgae. PLANT MOLECULAR BIOLOGY 2015; 89:309-18. [PMID: 26350402 DOI: 10.1007/s11103-015-0370-6] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 08/24/2015] [Indexed: 05/18/2023]
Abstract
Most microalgae produce triacylglycerol (TAG) under stress conditions such as nitrogen depletion, but the underlying molecular mechanism remains unclear. In this study, we focused on the role of target of rapamycin (TOR) in TAG accumulation. TOR is a serine/threonine protein kinase that is highly conserved and plays pivotal roles in nitrogen and other signaling pathways in eukaryotes. We previously constructed a rapamycin-susceptible Cyanidioschyzon merolae, a unicellular red alga, by expressing yeast FKBP12 protein to evaluate the results of TOR inhibition (Imamura et al. in Biochem Biophys Res Commun 439:264-269, 2013). By using this strain, we here report that rapamycin-induced TOR inhibition results in accumulation of cytoplasmic lipid droplets containing TAG. Transcripts for TAG synthesis-related genes, such as glycerol-3-phosphate acyltransferase and acyl-CoA:diacylglycerol acyltransferase (DGAT), were increased by rapamycin treatment. We also found that fatty acid synthase-dependent de novo fatty acid synthesis was required for the accumulation of lipid droplets. Induction of TAG and up-regulation of DGAT gene expression by rapamycin were similarly observed in the unicellular green alga, Chlamydomonas reinhardtii. These results suggest the general involvement of TOR signaling in TAG accumulation in divergent microalgae.
Collapse
Affiliation(s)
- Sousuke Imamura
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama, 332-0012, Japan.
| | - Yasuko Kawase
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Ikki Kobayashi
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Toshiyuki Sone
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
| | - Atsuko Era
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama, 332-0012, Japan
- Department of Cell Genetics, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Shin-Ya Miyagishima
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama, 332-0012, Japan
- Department of Cell Genetics, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Mie Shimojima
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-B1 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan
| | - Hiroyuki Ohta
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama, 332-0012, Japan
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-B1 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Kan Tanaka
- Chemical Resources Laboratory, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama, 332-0012, Japan.
| |
Collapse
|
47
|
Ohnuma M, Yokoyama T, Inouye T, Sekine Y, Kuroiwa T, Tanaka K. Optimization of polyethylene glycol (PEG)-mediated DNA introduction conditions for transient gene expression in the unicellular red alga Cyanidioschyzon merolae. J GEN APPL MICROBIOL 2015; 60:156-9. [PMID: 25273989 DOI: 10.2323/jgam.60.156] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Mio Ohnuma
- Institute of Molecular and Cellular Biosciences, The University of Tokyo
| | | | | | | | | | | |
Collapse
|
48
|
Bhardwaj D, Medici A, Gojon A, Lacombe B, Tuteja N. A new insight into root responses to external cues: Paradigm shift in nutrient sensing. PLANT SIGNALING & BEHAVIOR 2015; 10:e1049791. [PMID: 26146897 PMCID: PMC4854350 DOI: 10.1080/15592324.2015.1049791] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 05/06/2015] [Accepted: 05/06/2015] [Indexed: 05/25/2023]
Abstract
Higher plants are sessile and their growth relies on nutrients present in the soil. The acquisition of nutrients is challenging for plants. Phosphate and nitrate sensing and signaling cascades play significant role during adverse conditions of nutrient unavailability. Therefore, it is important to dissect the mechanism by which plant roots acquire nutrients from the soil. Root system architecture (RSA) exhibits extensive developmental flexibility and changes during nutrient stress conditions. Growth of root system in response to external concentration of nutrients is a joint operation of sensor or receptor proteins along with several other cytoplasmic accessory proteins. After nutrient sensing, sensor proteins start the cellular relay involving transcription factors, kinases, ubiquitin ligases and miRNA. The complexity of nutrient sensing is still nebulous and many new players need to be better studied. This review presents a survey of recent paradigm shift in the advancements in nutrient sensing in relation to plant roots.
Collapse
Affiliation(s)
- Deepak Bhardwaj
- International Center for Genetic Engineering & Biotechnology; Aruna Asaf Ali Marg; New Delhi, India
| | - Anna Medici
- Laboratoire de Biochimie et Physiologie Moléculaire des Plantes; UMR CNRS/INRA/SupAgro/UM; Institut de Biologie Intégrative des Plantes “Claude Grignon”; Montpellier cedex, France
| | - Alain Gojon
- Laboratoire de Biochimie et Physiologie Moléculaire des Plantes; UMR CNRS/INRA/SupAgro/UM; Institut de Biologie Intégrative des Plantes “Claude Grignon”; Montpellier cedex, France
| | - Benoît Lacombe
- Laboratoire de Biochimie et Physiologie Moléculaire des Plantes; UMR CNRS/INRA/SupAgro/UM; Institut de Biologie Intégrative des Plantes “Claude Grignon”; Montpellier cedex, France
| | - Narendra Tuteja
- International Center for Genetic Engineering & Biotechnology; Aruna Asaf Ali Marg; New Delhi, India
| |
Collapse
|
49
|
Fujiwara T, Kanesaki Y, Hirooka S, Era A, Sumiya N, Yoshikawa H, Tanaka K, Miyagishima SY. A nitrogen source-dependent inducible and repressible gene expression system in the red alga Cyanidioschyzon merolae. FRONTIERS IN PLANT SCIENCE 2015; 6:657. [PMID: 26379685 PMCID: PMC4549557 DOI: 10.3389/fpls.2015.00657] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 08/10/2015] [Indexed: 05/19/2023]
Abstract
The unicellular red alga Cyanidioschyzon merolae is a model organism for studying the basic biology of photosynthetic organisms. The C. merolae cell is composed of an extremely simple set of organelles. The genome is completely sequenced. Gene targeting and a heat-shock inducible gene expression system has been recently established. However, a conditional gene knockdown system has not been established, which is required for the examination of function of genes that are essential to cell viability and primary mutant defects. In the current study, we first evaluated the expression of a transgene from two chromosomal neutral loci located in the intergenic region between CMD184C and CMD185C, and a region upstream of the URA5.3 gene. There was no significant difference in expression between them and this result suggests that both may be used as neutral loci. We then designed an inducible and repressible gene expression by using promoters of nitrate-assimilation genes. The expression of nitrate-assimilation genes such as NR (nitrate reductase), NIR (nitrite reductase), and NRT (the nitrate/nitrite transporter) are reversibly regulated by their dependence on nitrogen sources. We constructed stable strains in which a cassette containing the NR, NIR, or NRT promoter and sfGFP gene was inserted in a region upstream of URA5.3 and examined the efficacy of the promoters. The NR, NIR, and NRT promoters were constitutively activated in the nitrate medium, whereas their activities were extremely low in presence of ammonium. The activation of each promoter was immediately inhibited within a period of 1 h by the addition of ammonium. Thus, a conditional knockdown system in C. merolae was successfully established. The activity varies among the promoters, and each is selectable according to the expression level of a target gene estimated by RNA-sequencing. This method is applicable to defects in genes of interest in photosynthetic organism.
Collapse
Affiliation(s)
- Takayuki Fujiwara
- Department of Cell Genetics, National Institute of GeneticsMishima, Japan
- *Correspondence: Takayuki Fujiwara and Shin-Ya Miyagishima, Department of Cell Genetics, National Institute of Genetics, 1111 Yata, Mishima 411-8540, Shizuoka, Japan, ;
| | - Yu Kanesaki
- NODAI Genome Research Center, Tokyo University of AgricultureTokyo, Japan
| | - Shunsuke Hirooka
- Department of Cell Genetics, National Institute of GeneticsMishima, Japan
- Japan Science and Technology Agency, Core Research for Evolutional Science and TechnologyKawaguchi, Japan
| | - Atsuko Era
- Department of Cell Genetics, National Institute of GeneticsMishima, Japan
- Japan Science and Technology Agency, Core Research for Evolutional Science and TechnologyKawaguchi, Japan
| | - Nobuko Sumiya
- Department of Cell Genetics, National Institute of GeneticsMishima, Japan
- Japan Science and Technology Agency, Core Research for Evolutional Science and TechnologyKawaguchi, Japan
| | - Hirofumi Yoshikawa
- Japan Science and Technology Agency, Core Research for Evolutional Science and TechnologyKawaguchi, Japan
- Department of Bioscience, Tokyo University of AgricultureTokyo, Japan
| | - Kan Tanaka
- Japan Science and Technology Agency, Core Research for Evolutional Science and TechnologyKawaguchi, Japan
- Chemical Resources Laboratory, Tokyo Institute of TechnologyYokohama, Japan
| | - Shin-Ya Miyagishima
- Department of Cell Genetics, National Institute of GeneticsMishima, Japan
- Japan Science and Technology Agency, Core Research for Evolutional Science and TechnologyKawaguchi, Japan
- Department of Genetics, Graduate University for Advanced StudiesMishima, Japan
- *Correspondence: Takayuki Fujiwara and Shin-Ya Miyagishima, Department of Cell Genetics, National Institute of Genetics, 1111 Yata, Mishima 411-8540, Shizuoka, Japan, ;
| |
Collapse
|
50
|
Development of a heat-shock inducible gene expression system in the red alga Cyanidioschyzon merolae. PLoS One 2014; 9:e111261. [PMID: 25337786 PMCID: PMC4206486 DOI: 10.1371/journal.pone.0111261] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 09/26/2014] [Indexed: 11/19/2022] Open
Abstract
The cell of the unicellular red alga Cyanidioschyzon merolae contains a single chloroplast and mitochondrion, the division of which is tightly synchronized by a light/dark cycle. The genome content is extremely simple, with a low level of genetic redundancy, in photosynthetic eukaryotes. In addition, transient transformation and stable transformation by homologous recombination have been reported. However, for molecular genetic analyses of phenomena that are essential for cellular growth and survival, inducible gene expression/suppression systems are needed. Here, we report the development of a heat-shock inducible gene expression system in C. merolae. CMJ101C, encoding a small heat shock protein, is transcribed only when cells are exposed to an elevated temperature. Using a superfolder GFP as a reporter protein, the 200-bp upstream region of CMJ101C orf was determined to be the optimal promoter for heat-shock induction. The optimal temperature to induce expression is 50°C, at which C. merolae cells are able to proliferate. At least a 30-min heat shock is required for the expression of a protein of interest and a 60-min heat shock yields the maximum level of protein expression. After the heat shock, the mRNA level decreases rapidly. As an example of the system, the expression of a dominant negative form of chloroplast division DRP5B protein, which has a mutation in the GTPase domain, was induced. Expression of the dominant negative DRP5B resulted in the appearance of aberrant-shaped cells in which two daughter chloroplasts and the cells are still connected by a small DRP5B positive tube-like structure. This result suggests that the dominant negative DRP5B inhibited the final scission of the chloroplast division site, but not the earlier stages of division site constriction. It is also suggested that cell cycle progression is not arrested by the impairment of chloroplast division at the final stage.
Collapse
|