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Sui J, Cui Y, Zhang J, Li S, Zhao Y, Bai M, Feng G, Wu H. Enhanced biomass production and harvesting efficiency of Chlamydomonas reinhardtii under high-ammonium conditions by powdered oyster shell. BIORESOURCE TECHNOLOGY 2024; 403:130904. [PMID: 38801957 DOI: 10.1016/j.biortech.2024.130904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 05/23/2024] [Accepted: 05/24/2024] [Indexed: 05/29/2024]
Abstract
Chlamydomonas reinhardtii prefers ammonium (NH4+) as a nitrogen source, but its late-stage growth under high-NH4+ concentrations (0.5 ∼ 1 g/L) is retarded due to medium acidification. In this study, oyster shell powders were shown to increase the tolerance of C. reinhardtii to NH4+ supplementation at 0.7 g/L in TAP medium in 1-L bubble-column bioreactors, resulting in a 22.9 % increase in biomass production, 62.1 % rise in unsaturated fatty acid accumulation, and 19.2 % improvement in harvesting efficiency. Powdered oyster shell mitigated medium acidification (pH 7.2-7.8) and provided dissolved inorganic carbon up to 8.02 × 103 μmol/L, facilitating a 76.3 % NH4+ consumption, release of up to 189 mg/L of Ca2+, a 42.1 % reduction in ζ-potential and 27.7 % increase in flocculation activity of microalgae cells. This study highlights a promising approach to utilize powdered oyster shell as a liming agent, supplement carbon source, and bio-flocculant for enhancing biomass production and microalgae harvesting in NH4+-rich environments.
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Affiliation(s)
- Jikang Sui
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao, Shandong Province 266003, China
| | - Yuxuan Cui
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao, Shandong Province 266003, China
| | - Jinku Zhang
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao, Shandong Province 266003, China
| | - Shiyang Li
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao, Shandong Province 266003, China
| | - Yue Zhao
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao, Shandong Province 266003, China
| | - Mingkai Bai
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao, Shandong Province 266003, China
| | - Guangxin Feng
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao, Shandong Province 266003, China.
| | - Haohao Wu
- State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao, Shandong Province 266003, China.
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2
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Nanes Sarfati D, Xue Y, Song ES, Byrne A, Le D, Darmanis S, Quake SR, Burlacot A, Sikes J, Wang B. Coordinated wound responses in a regenerative animal-algal holobiont. Nat Commun 2024; 15:4032. [PMID: 38740753 DOI: 10.1038/s41467-024-48366-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 04/24/2024] [Indexed: 05/16/2024] Open
Abstract
Animal regeneration involves coordinated responses across cell types throughout the animal body. In endosymbiotic animals, whether and how symbionts react to host injury and how cellular responses are integrated across species remain unexplored. Here, we study the acoel Convolutriloba longifissura, which hosts symbiotic Tetraselmis sp. green algae and can regenerate entire bodies from tissue fragments. We show that animal injury causes a decline in the photosynthetic efficiency of the symbiotic algae, alongside two distinct, sequential waves of transcriptional responses in acoel and algal cells. The initial algal response is characterized by the upregulation of a cohort of photosynthesis-related genes, though photosynthesis is not necessary for regeneration. A conserved animal transcription factor, runt, is induced after injury and required for acoel regeneration. Knockdown of Cl-runt dampens transcriptional responses in both species and further reduces algal photosynthetic efficiency post-injury. Our results suggest that the holobiont functions as an integrated unit of biological organization by coordinating molecular networks across species through the runt-dependent animal regeneration program.
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Affiliation(s)
| | - Yuan Xue
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Eun Sun Song
- Department of Applied Physics, Stanford University, Stanford, CA, USA
| | | | - Daniel Le
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | | | - Stephen R Quake
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Applied Physics, Stanford University, Stanford, CA, USA
| | - Adrien Burlacot
- Department of Biology, Stanford University, Stanford, CA, USA
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
| | - James Sikes
- Department of Biology, University of San Francisco, San Francisco, CA, USA.
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA, USA.
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA.
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3
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Sawant KR, Sarnaik AP, Singh R, Savvashe P, Baier T, Kruse O, Jutur PP, Lali A, Pandit RA. Outdoor cultivation and metabolomics exploration of Chlamydomonas engineered for bisabolene production. BIORESOURCE TECHNOLOGY 2024; 398:130513. [PMID: 38432540 DOI: 10.1016/j.biortech.2024.130513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/27/2024] [Accepted: 02/29/2024] [Indexed: 03/05/2024]
Abstract
Demonstrating outdoor cultivation of engineered microalgae at considerable scales is essential for their prospective large-scale deployment. Hence, this study focuses on the outdoor cultivation of an engineered Chlamydomonas reinhardtii strain, 3XAgBs-SQs, for bisabolene production under natural dynamic conditions of light and temperature. Our preliminary outdoor experiments showed improved growth, but frequent culture collapses in conventional Tris-acetate-phosphate medium. In contrast, modified high-salt medium (HSM) supported prolonged cell survival, outdoor. However, their subsequent outdoor scale-up from 250 mL to 5 L in HSM was effective with 10 g/L bicarbonate supplementation. Pulse amplitude modulation fluorometry and metabolomic analysis further validated their improved photosynthesis and uncompromised metabolic fluxes towards the biomass and the products (natural carotenoids and engineered bisabolene). These strains could produce 906 mg/L bisabolene and 54 mg/L carotenoids, demonstrating the first successful outdoor photoautotrophic cultivation of engineeredC. reinhardtii,establishing it as a one-cell two-wells biorefinery.
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Affiliation(s)
- Kaustubh R Sawant
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Matunga, Mumbai 400019, India.
| | - Aditya P Sarnaik
- School for Sustainable Engineering and the Built Environment, Arizona State University, The Polytechnic Campus, Mesa, AZ 85212, USA.
| | - Rabinder Singh
- Omics of Algae Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India; Laboratory of Cell Cycles of Algae, Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, 237, Trebon 379 01, Czech Republic.
| | - Prashant Savvashe
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Matunga, Mumbai 400019, India.
| | - Thomas Baier
- Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universitätsstrasse 27, 33615 Bielefeld, Germany.
| | - Olaf Kruse
- Bielefeld University, Faculty of Biology, Center for Biotechnology (CeBiTec), Universitätsstrasse 27, 33615 Bielefeld, Germany.
| | - Pannaga Pavan Jutur
- Omics of Algae Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India.
| | - Arvind Lali
- Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai 400019, India.
| | - Reena A Pandit
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Matunga, Mumbai 400019, India.
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4
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Clapero V, Arrivault S, Stitt M. Natural variation in metabolism of the Calvin-Benson cycle. Semin Cell Dev Biol 2024; 155:23-36. [PMID: 36959059 DOI: 10.1016/j.semcdb.2023.02.015] [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: 08/24/2022] [Revised: 02/24/2023] [Accepted: 02/24/2023] [Indexed: 03/25/2023]
Abstract
The Calvin-Benson cycle (CBC) evolved over 2 billion years ago but has been subject to massive selection due to falling atmospheric carbon dioxide, rising atmospheric oxygen and changing nutrient and water availability. In addition, large groups of organisms have evolved carbon-concentrating mechanisms (CCMs) that operate upstream of the CBC. Most previous studies of CBC diversity focused on Rubisco kinetics and regulation. Quantitative metabolite profiling provides a top-down strategy to uncover inter-species diversity in CBC operation. CBC profiles were recently published for twenty species including terrestrial C3 species, terrestrial C4 species that operate a biochemical CCM, and cyanobacteria and green algae that operate different types of biophysical CCM. Distinctive profiles were found for species with different modes of photosynthesis, revealing that evolution of the various CCMs was accompanied by co-evolution of the CBC. Diversity was also found between species that share the same mode of photosynthesis, reflecting lineage-dependent diversity of the CBC. Connectivity analysis uncovers constraints due to pathway and thermodynamic topology, and reveals that cross-species diversity in the CBC is driven by changes in the balance between regulated enzymes and in the balance between the CBC and the light reactions or end-product synthesis.
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Affiliation(s)
- Vittoria Clapero
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, Golm, D-14476 Potsdam, Germany
| | - Stéphanie Arrivault
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, Golm, D-14476 Potsdam, Germany.
| | - Mark Stitt
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, Golm, D-14476 Potsdam, Germany
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5
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Choi BY, Park H, Kim J, Wang S, Lee J, Lee Y, Shim D. BLZ8 activates a plastidial peroxiredoxin and a ferredoxin to protect Chlamydomonas reinhardtii against oxidative stress. PLANT BIOLOGY (STUTTGART, GERMANY) 2023; 25:915-923. [PMID: 37338124 DOI: 10.1111/plb.13552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 06/05/2023] [Indexed: 06/21/2023]
Abstract
Reactive oxygen species (ROS) cause damage to various cellular processes in almost all organisms, in particular photosynthetic organisms that depend on the electron transfer chain for CO2 fixation. However, the detoxifying process to mitigate ROS damage has not been studied intensively in microalgae. Here, we characterized the ROS detoxifying role of a bZIP transcription factor, BLZ8, in Chlamydomonas reinhardtii. To identify downstream targets of BLZ8, we carried out comparative genome-wide transcriptomic profiling of BLZ8 OX and its parental CC-4533 under oxidative stress conditions. Luciferase reporter activity assays and RT-qPCR were performed to test whether BLZ8 regulates downstream genes. We performed an in silico functional gene network analysis and an in vivo immunoprecipitation assay to identify the interaction between downstream targets of BLZ8. Comparative transcriptomic analysis and RT-qPCR revealed that overexpression of BLZ8 increased the expression levels of plastid peroxiredoxin1 (PRX1) and ferredoxin-5 (FDX5) under oxidative stress conditions. BLZ8 alone could activate the transcriptional activity of FDX5 and required bZIP2 to activate transcriptional activity of PRX1. Functional gene network analysis using FDX5 and PRX1 orthologs in A. thaliana suggested that these two genes were functionally associated. Indeed, our immunoprecipitation assay revealed the physical interaction between PRX1 and FDX5. Furthermore, the complemented strain, fdx5 (FDX5), recovered growth retardation of the fdx5 mutant under oxidative stress conditions, indicating that FDX5 contributes to oxidative stress tolerance. These results suggest that BLZ8 activates PRX1 and FDX5 expression, resulting in the detoxification of ROS to confer oxidative stress tolerance in microalgae.
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Affiliation(s)
- B Y Choi
- Department of Biological Sciences, Chungnam National University, Daejeon, Korea
| | - H Park
- Department of Biological Sciences, Chungnam National University, Daejeon, Korea
| | - J Kim
- Department of Biological Sciences, Chungnam National University, Daejeon, Korea
| | - S Wang
- Division of Natural and Applied Sciences, Duke Kunshan University, Suzhou, China
| | - J Lee
- Division of Natural and Applied Sciences, Duke Kunshan University, Suzhou, China
| | - Y Lee
- Department of Life Science, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - D Shim
- Department of Biological Sciences, Chungnam National University, Daejeon, Korea
- Center for Genome Engineering, Institute for Basic Science, Daejeon, Korea
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6
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He S, Crans VL, Jonikas MC. The pyrenoid: the eukaryotic CO2-concentrating organelle. THE PLANT CELL 2023; 35:3236-3259. [PMID: 37279536 PMCID: PMC10473226 DOI: 10.1093/plcell/koad157] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 05/09/2023] [Accepted: 05/17/2023] [Indexed: 06/08/2023]
Abstract
The pyrenoid is a phase-separated organelle that enhances photosynthetic carbon assimilation in most eukaryotic algae and the land plant hornwort lineage. Pyrenoids mediate approximately one-third of global CO2 fixation, and engineering a pyrenoid into C3 crops is predicted to boost CO2 uptake and increase yields. Pyrenoids enhance the activity of the CO2-fixing enzyme Rubisco by supplying it with concentrated CO2. All pyrenoids have a dense matrix of Rubisco associated with photosynthetic thylakoid membranes that are thought to supply concentrated CO2. Many pyrenoids are also surrounded by polysaccharide structures that may slow CO2 leakage. Phylogenetic analysis and pyrenoid morphological diversity support a convergent evolutionary origin for pyrenoids. Most of the molecular understanding of pyrenoids comes from the model green alga Chlamydomonas (Chlamydomonas reinhardtii). The Chlamydomonas pyrenoid exhibits multiple liquid-like behaviors, including internal mixing, division by fission, and dissolution and condensation in response to environmental cues and during the cell cycle. Pyrenoid assembly and function are induced by CO2 availability and light, and although transcriptional regulators have been identified, posttranslational regulation remains to be characterized. Here, we summarize the current knowledge of pyrenoid function, structure, components, and dynamic regulation in Chlamydomonas and extrapolate to pyrenoids in other species.
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Affiliation(s)
- Shan He
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
- Howard Hughes Medical Institute, Princeton University, Princeton, NJ 08540, USA
| | - Victoria L Crans
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
| | - Martin C Jonikas
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
- Howard Hughes Medical Institute, Princeton University, Princeton, NJ 08540, USA
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7
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Kanna Dasan Y, Lam MK, Chai YH, Lim JW, Ho YC, Tan IS, Lau SY, Show PL, Lee KT. Unlocking the potential of microalgae bio-factories for carbon dioxide mitigation: A comprehensive exploration of recent advances, key challenges, and energy-economic insights. BIORESOURCE TECHNOLOGY 2023; 380:129094. [PMID: 37100295 DOI: 10.1016/j.biortech.2023.129094] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 04/17/2023] [Accepted: 04/23/2023] [Indexed: 05/14/2023]
Abstract
Microalgae are promising alternatives to mitigate atmospheric CO2 owing to their fast growth rates, resilience in the face of adversity and ability to produce a wide range of products, including food, feed supplements, chemicals, and biofuels. However, to fully harness the potential of microalgae-based carbon capture technology, further advancements are required to overcome the associated challenges and limitations, particularly with regards to enhancing CO2 solubility in the culture medium. This review provides an in-depth analysis of the biological carbon concentrating mechanism and highlights the current approaches, including species selection, optimization of hydrodynamics, and abiotic components, aimed at improving the efficacy of CO2 solubility and biofixation. Moreover, cutting-edge strategies such as gene mutation, bubble dynamics and nanotechnology are systematically outlined to elevate the CO2 biofixation capacity of microalgal cells. The review also evaluates the energy and economic feasibility of using microalgae for CO2 bio-mitigation, including challenges and prospects for future development.
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Affiliation(s)
- Yaleeni Kanna Dasan
- Chemical Engineering Department, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia; HICoE-Centre for Biofuel and Biochemical Research, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia
| | - Man Kee Lam
- Chemical Engineering Department, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia; HICoE-Centre for Biofuel and Biochemical Research, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia.
| | - Yee Ho Chai
- Chemical Engineering Department, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia; HICoE-Centre for Biofuel and Biochemical Research, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia
| | - Jun Wei Lim
- HICoE-Centre for Biofuel and Biochemical Research, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia; Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia
| | - Yeek Chia Ho
- Centre for Urban Resource Sustainability, Civil and Environmental Engineering Department, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS, Seri Iskandar 32610, Perak, Malaysia
| | - Inn Shi Tan
- Department of Chemical and Energy Engineering, Faculty of Engineering and Science, Curtin University Malaysia, CDT 250, 98009 Miri, Sarawak, Malaysia
| | - Sie Yon Lau
- Department of Chemical and Energy Engineering, Faculty of Engineering and Science, Curtin University Malaysia, CDT 250, 98009 Miri, Sarawak, Malaysia
| | - Pau Loke Show
- Department of Chemical Engineering, Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates; Zhejiang Provincial Key Laboratory for Subtropical Water Environment and Marine Biological Resources Protection, Wenzhou University, Wenzhou 325035, China; Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia, Jalan Broga, 43500 Semenyih, Selangor, Malaysia; Department of Sustainable Engineering, Saveetha School of Engineering, SIMATS, Chennai 602105, India
| | - Keat Teong Lee
- School of Chemical Engineering, Universiti Sains Malaysia, Engineering Campus, Penang, Nibong Tebal 14300, Malaysia
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8
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Burlacot A, Peltier G. Energy crosstalk between photosynthesis and the algal CO 2-concentrating mechanisms. TRENDS IN PLANT SCIENCE 2023; 28:795-807. [PMID: 37087359 DOI: 10.1016/j.tplants.2023.03.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 03/16/2023] [Accepted: 03/18/2023] [Indexed: 05/03/2023]
Abstract
Microalgal photosynthesis is responsible for nearly half of the CO2 annually captured by Earth's ecosystems. In aquatic environments where the CO2 availability is low, the CO2-fixing efficiency of microalgae greatly relies on mechanisms - called CO2-concentrating mechanisms (CCMs) - for concentrating CO2 at the catalytic site of the CO2-fixing enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). While the transport of inorganic carbon (Ci) across membrane bilayers against a concentration gradient consumes part of the chemical energy generated by photosynthesis, the bioenergetics and cellular mechanisms involved are only beginning to be elucidated. Here, we review the current knowledge relating to the energy requirement of CCMs in the light of recent advances in photosynthesis regulatory mechanisms and the spatial organization of CCM components.
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Affiliation(s)
- Adrien Burlacot
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA; Department of Biology, Stanford University, Stanford, CA 94305, USA.
| | - Gilles Peltier
- Aix-Marseille Université, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France.
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9
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Shimamura D, Yamano T, Niikawa Y, Hu D, Fukuzawa H. A pyrenoid-localized protein SAGA1 is necessary for Ca 2+-binding protein CAS-dependent expression of nuclear genes encoding inorganic carbon transporters in Chlamydomonas reinhardtii. PHOTOSYNTHESIS RESEARCH 2023; 156:181-192. [PMID: 36656499 DOI: 10.1007/s11120-022-00996-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 12/14/2022] [Indexed: 05/03/2023]
Abstract
Microalgae induce a CO2-concentrating mechanism (CCM) to maintain photosynthetic affinity for dissolved inorganic carbon (Ci) under CO2-limiting conditions. In the model alga Chlamydomonas reinhardtii, the pyrenoid-localized Ca2+-binding protein CAS is required to express genes encoding the Ci-transporters, high-light activated 3 (HLA3), and low-CO2-inducible protein A (LCIA). To identify new factors related to the regulation or components of the CCM, we isolated CO2-requiring mutants KO-60 and KO-62. These mutants had insertions of a hygromycin-resistant cartridge in the StArch Granules Abnormal 1 (SAGA1) gene, which is necessary to maintain the number of pyrenoids and the structure of pyrenoid tubules in the chloroplast. In both KO-60 and the previously identified saga1 mutant, expression levels of 532 genes were significantly reduced. Among them, 10 CAS-dependent genes, including HLA3 and LCIA, were not expressed in the saga1 mutants. While CAS was expressed normally at the protein levels, the localization of CAS was dispersed through the chloroplast rather than in the pyrenoid, even under CO2-limiting conditions. These results suggest that SAGA1 is necessary not only for maintenance of the pyrenoid structure but also for regulation of the nuclear genes encoding Ci-transporters through CAS-dependent retrograde signaling under CO2-limiting stress.
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Affiliation(s)
- Daisuke Shimamura
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Takashi Yamano
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan.
| | - Yuki Niikawa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Donghui Hu
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan.
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10
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Chen D, Wang G, Chen C, Feng Z, Jiang Y, Yu H, Li M, Chao Y, Tang Y, Wang S, Qiu R. The interplay between microalgae and toxic metal(loid)s: mechanisms and implications in AMD phycoremediation coupled with Fe/Mn mineralization. JOURNAL OF HAZARDOUS MATERIALS 2023; 454:131498. [PMID: 37146335 DOI: 10.1016/j.jhazmat.2023.131498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 04/10/2023] [Accepted: 04/24/2023] [Indexed: 05/07/2023]
Abstract
Acid mine drainage (AMD) is low-pH with high concentration of sulfates and toxic metal(loid)s (e.g. As, Cd, Pb, Cu, Zn), thereby posing a global environmental problem. For decades, microalgae have been used to remediate metal(loid)s in AMD, as they have various adaptive mechanisms for tolerating extreme environmental stress. Their main phycoremediation mechanisms are biosorption, bioaccumulation, coupling with sulfate-reducing bacteria, alkalization, biotransformation, and Fe/Mn mineral formation. This review summarizes how microalgae cope with metal(loid) stress and their specific mechanisms of phycoremediation in AMD. Based on the universal physiological characteristics of microalgae and the properties of their secretions, several Fe/Mn mineralization mechanisms induced by photosynthesis, free radicals, microalgal-bacterial reciprocity, and algal organic matter are proposed. Notably, microalgae can also reduce Fe(III) and inhibit mineralization, which is environmentally unfavorable. Therefore, the comprehensive environmental effects of microalgal co-occurring and cyclical opposing processes must be carefully considered. Using chemical and biological perspectives, this review innovatively proposes several specific processes and mechanisms of Fe/Mn mineralization that are mediated by microalgae, providing a theoretical basis for the geochemistry of metal(loid)s and natural attenuation of pollutants in AMD.
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Affiliation(s)
- Daijie Chen
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Guobao Wang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory for Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Chiyu Chen
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Zekai Feng
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Yuanyuan Jiang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Hang Yu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Mengyao Li
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Yuanqing Chao
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory for Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Yetao Tang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory for Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China
| | - Shizhong Wang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory for Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China.
| | - Rongliang Qiu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
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11
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Kupriyanova EV, Pronina NA, Los DA. Adapting from Low to High: An Update to CO 2-Concentrating Mechanisms of Cyanobacteria and Microalgae. PLANTS (BASEL, SWITZERLAND) 2023; 12:1569. [PMID: 37050194 PMCID: PMC10096703 DOI: 10.3390/plants12071569] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 06/19/2023]
Abstract
The intracellular accumulation of inorganic carbon (Ci) by microalgae and cyanobacteria under ambient atmospheric CO2 levels was first documented in the 80s of the 20th Century. Hence, a third variety of the CO2-concentrating mechanism (CCM), acting in aquatic photoautotrophs with the C3 photosynthetic pathway, was revealed in addition to the then-known schemes of CCM, functioning in CAM and C4 higher plants. Despite the low affinity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) of microalgae and cyanobacteria for the CO2 substrate and low CO2/O2 specificity, CCM allows them to perform efficient CO2 fixation in the reductive pentose phosphate (RPP) cycle. CCM is based on the coordinated operation of strategically located carbonic anhydrases and CO2/HCO3- uptake systems. This cooperation enables the intracellular accumulation of HCO3-, which is then employed to generate a high concentration of CO2 molecules in the vicinity of Rubisco's active centers compensating up for the shortcomings of enzyme features. CCM functions as an add-on to the RPP cycle while also acting as an important regulatory link in the interaction of dark and light reactions of photosynthesis. This review summarizes recent advances in the study of CCM molecular and cellular organization in microalgae and cyanobacteria, as well as the fundamental principles of its functioning and regulation.
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12
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Förster B, Rourke LM, Weerasooriya HN, Pabuayon ICM, Rolland V, Au EK, Bala S, Bajsa-Hirschel J, Kaines S, Kasili R, LaPlace L, Machingura MC, Massey B, Rosati VC, Stuart-Williams H, Badger MR, Price GD, Moroney JV. The Chlamydomonas reinhardtii chloroplast envelope protein LCIA transports bicarbonate in planta. JOURNAL OF EXPERIMENTAL BOTANY 2023:erad116. [PMID: 36987927 DOI: 10.1093/jxb/erad116] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Indexed: 06/19/2023]
Abstract
LCIA is a chloroplast envelope protein associated with the CO2 concentrating mechanism of the green alga Chlamydomonas reinhardtii. LCIA is postulated to be a HCO3- channel, but previous studies were unable to show that LCIA was actively transporting bicarbonate in planta. Therefore, LCIA activity was investigated more directly in two heterologous systems: an E. coli mutant (DCAKO) lacking both native carbonic anhydrases and an Arabidopsis mutant (βca5) missing the plastid carbonic anhydrase βCA5. Both DCAKO and βca5 cannot grow in ambient CO2 conditions, as they lack carbonic anhydrase-catalyzed production of the necessary HCO3- concentration for lipid and nucleic acid biosynthesis. Expression of LCIA restored growth in both systems in ambient CO2 conditions, which strongly suggests that LCIA is facilitating HCO3- uptake in each system. To our knowledge, this is the first direct evidence that LCIA moves HCO3- across membranes in bacteria and plants. Furthermore, the βca5 plant bioassay used in this study is the first system for testing HCO3- transport activity in planta, an experimental breakthrough that will be valuable for future studies aimed at improving the photosynthetic efficiency of crop plants using components from algal CO2 concentrating mechanisms.
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Affiliation(s)
- Britta Förster
- The Australian National University, Canberra, ACT 2600, Australia
| | - Loraine M Rourke
- The Australian National University, Canberra, ACT 2600, Australia
| | - Hiruni N Weerasooriya
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Isaiah C M Pabuayon
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Vivien Rolland
- CSIRO Agriculture and Food, Canberra, ACT 2601, Australia
| | - Eng Kee Au
- The Australian National University, Canberra, ACT 2600, Australia
| | - Soumi Bala
- The Australian National University, Canberra, ACT 2600, Australia
| | - Joanna Bajsa-Hirschel
- Natural Products Utilization Research Unit, United States Department of Agriculture, University, MS 38677, USA
| | - Sarah Kaines
- The Australian National University, Canberra, ACT 2600, Australia
| | - Remmy Kasili
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Lillian LaPlace
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | | | - Baxter Massey
- The Australian National University, Canberra, ACT 2600, Australia
| | - Viviana C Rosati
- Department of Biology, Centre for Novel Agricultural Products (CNAP), University of York, Wentworth Way, York YO10 5DD, UK
| | | | - Murray R Badger
- The Australian National University, Canberra, ACT 2600, Australia
| | - G Dean Price
- The Australian National University, Canberra, ACT 2600, Australia
| | - James V Moroney
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
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13
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Rosado-Souza L, Yokoyama R, Sonnewald U, Fernie AR. Understanding source-sink interactions: Progress in model plants and translational research to crops. MOLECULAR PLANT 2023; 16:96-121. [PMID: 36447435 DOI: 10.1016/j.molp.2022.11.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/27/2022] [Accepted: 11/25/2022] [Indexed: 06/16/2023]
Abstract
Agriculture is facing a massive increase in demand per hectare as a result of an ever-expanding population and environmental deterioration. While we have learned much about how environmental conditions and diseases impact crop yield, until recently considerably less was known concerning endogenous factors, including within-plant nutrient allocation. In this review, we discuss studies of source-sink interactions covering both fundamental research in model systems under controlled growth conditions and how the findings are being translated to crop plants in the field. In this respect we detail efforts aimed at improving and/or combining C3, C4, and CAM modes of photosynthesis, altering the chloroplastic electron transport chain, modulating photorespiration, adopting bacterial/algal carbon-concentrating mechanisms, and enhancing nitrogen- and water-use efficiencies. Moreover, we discuss how modulating TCA cycle activities and primary metabolism can result in increased rates of photosynthesis and outline the opportunities that evaluating natural variation in photosynthesis may afford. Although source, transport, and sink functions are all covered in this review, we focus on discussing source functions because the majority of research has been conducted in this field. Nevertheless, considerable recent evidence, alongside the evidence from classical studies, demonstrates that both transport and sink functions are also incredibly important determinants of yield. We thus describe recent evidence supporting this notion and suggest that future strategies for yield improvement should focus on combining improvements in each of these steps to approach yield optimization.
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Affiliation(s)
- Laise Rosado-Souza
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany.
| | - Ryo Yokoyama
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
| | - Uwe Sonnewald
- Department of Biochemistry, University of Erlangen-Nuremberg, Staudtstrasse 5, 91058 Erlangen, Germany
| | - Alisdair R Fernie
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany.
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14
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Adler L, Díaz-Ramos A, Mao Y, Pukacz KR, Fei C, McCormick AJ. New horizons for building pyrenoid-based CO2-concentrating mechanisms in plants to improve yields. PLANT PHYSIOLOGY 2022; 190:1609-1627. [PMID: 35961043 PMCID: PMC9614477 DOI: 10.1093/plphys/kiac373] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 07/06/2022] [Indexed: 05/06/2023]
Abstract
Many photosynthetic species have evolved CO2-concentrating mechanisms (CCMs) to improve the efficiency of CO2 assimilation by Rubisco and reduce the negative impacts of photorespiration. However, the majority of plants (i.e. C3 plants) lack an active CCM. Thus, engineering a functional heterologous CCM into important C3 crops, such as rice (Oryza sativa) and wheat (Triticum aestivum), has become a key strategic ambition to enhance yield potential. Here, we review recent advances in our understanding of the pyrenoid-based CCM in the model green alga Chlamydomonas reinhardtii and engineering progress in C3 plants. We also discuss recent modeling work that has provided insights into the potential advantages of Rubisco condensation within the pyrenoid and the energetic costs of the Chlamydomonas CCM, which, together, will help to better guide future engineering approaches. Key findings include the potential benefits of Rubisco condensation for carboxylation efficiency and the need for a diffusional barrier around the pyrenoid matrix. We discuss a minimal set of components for the CCM to function and that active bicarbonate import into the chloroplast stroma may not be necessary for a functional pyrenoid-based CCM in planta. Thus, the roadmap for building a pyrenoid-based CCM into plant chloroplasts to enhance the efficiency of photosynthesis now appears clearer with new challenges and opportunities.
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Affiliation(s)
| | | | - Yuwei Mao
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Krzysztof Robin Pukacz
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Chenyi Fei
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, USA
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15
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Tsuji Y, Kinoshita A, Tsukahara M, Ishikawa T, Shinkawa H, Yamano T, Fukuzawa H. A YAK1-type protein kinase, triacylglycerol accumulation regulator 1, in the green alga Chlamydomonas reinhardtii is a potential regulator of cell division and differentiation into gametes during photoautotrophic nitrogen deficiency. J GEN APPL MICROBIOL 2022. [PMID: 36002293 DOI: 10.2323/jgam.2022.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Yet another kinase (YAK) 1 is a conserved eukaryotic protein kinase coordinating growth and development. We previously isolated a mutant of Chlamydomonas reinhardtii defective in the YAK1 ortholog triacylglycerol (TAG) accumulation regulator 1 (TAR1). The mutant tar1-1 displayed higher levels of chlorophyll, starch, TAG, and biomass than the parental strain C9 (renamed as C9-3) in photoautotrophic nitrogen (N)-deficient conditions. However, we found that the parental C9-3 showed faster chlorosis upon N-deficiency than the original C9 (C9-1) freshly recovered from cryopreservation, suggesting that C9-3 had acquired particular characteristics during long-term subculturing. To exclude phenotypes dependent on a particular parental strain, we newly created tar1 mutants from two wild-types, C9-1 and CC 125. Like tar1-1, the new tar1 mutants showed higher levels of chlorophyll and TAG/starch than the parental strain. Upon removal of N, Chlamydomonas cells divide once before ceasing further division. Previously, the single division after N-removal was arrested in tar1-1 in photomixotrophic conditions, but this phenotype was not observed in photoautotrophic conditions because of the particular characteristics of the parental C9-3. However, using C9- 1 and CC-125 as parental strains, we showed that cell division after N-removal was impaired in new tar1 mutants in photoautotrophic conditions. Consistent with the view that the division under N-deficiency is necessary for gametic differentiation, new tar1 mutants showed lower mating efficiency than the parental strains. Taken together, TAR1 was suggested to promote differentiation into gametes through the regulation of cell division in response to N-deficiency.
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Affiliation(s)
| | | | | | | | - Haruka Shinkawa
- Graduate Study of Biostudies, Kyoto University.,Present address: Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University
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16
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Chen J, Huang Y, Shu Y, Hu X, Wu D, Jiang H, Wang K, Liu W, Fu W. Recent Progress on Systems and Synthetic Biology of Diatoms for Improving Algal Productivity. Front Bioeng Biotechnol 2022; 10:908804. [PMID: 35646842 PMCID: PMC9136054 DOI: 10.3389/fbioe.2022.908804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 04/29/2022] [Indexed: 11/13/2022] Open
Abstract
Microalgae have drawn much attention for their potential applications as a sustainable source for developing bioactive compounds, functional foods, feeds, and biofuels. Diatoms, as one major group of microalgae with high yields and strong adaptability to the environment, have shown advantages in developing photosynthetic cell factories to produce value-added compounds, including heterologous bioactive products. However, the commercialization of diatoms has encountered several obstacles that limit the potential mass production, such as the limitation of algal productivity and low photosynthetic efficiency. In recent years, systems and synthetic biology have dramatically improved the efficiency of diatom cell factories. In this review, we discussed first the genome sequencing and genome-scale metabolic models (GEMs) of diatoms. Then, approaches to optimizing photosynthetic efficiency are introduced with a focus on the enhancement of biomass productivity in diatoms. We also reviewed genome engineering technologies, including CRISPR (clustered regularly interspaced short palindromic repeats) gene-editing to produce bioactive compounds in diatoms. Finally, we summarized the recent progress on the diatom cell factory for producing heterologous compounds through genome engineering to introduce foreign genes into host diatoms. This review also pinpointed the bottlenecks in algal engineering development and provided critical insights into the future direction of algal production.
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Affiliation(s)
- Jiwei Chen
- Department of Marine Science, Ocean College, Zhejiang University, Hangzhou, China
| | - Yifan Huang
- Department of Marine Science, Ocean College, Zhejiang University, Hangzhou, China
| | - Yuexuan Shu
- Department of Marine Science, Ocean College, Zhejiang University, Hangzhou, China
| | - Xiaoyue Hu
- Center for Data Science, Zhejiang University, Hangzhou, China
- School of Mathematical Sciences, Zhejiang University, Hangzhou, China
| | - Di Wu
- Department of Marine Science, Ocean College, Zhejiang University, Hangzhou, China
| | - Hangjin Jiang
- Center for Data Science, Zhejiang University, Hangzhou, China
| | - Kui Wang
- Department of Marine Science, Ocean College, Zhejiang University, Hangzhou, China
| | - Weihua Liu
- School of Mathematical Sciences, Zhejiang University, Hangzhou, China
| | - Weiqi Fu
- Department of Marine Science, Ocean College, Zhejiang University, Hangzhou, China
- Center for Systems Biology and Faculty of Industrial Engineering, Mechanical Engineering and Computer Science, School of Engineering and Natural Sciences, University of Iceland, Reykjavik, Iceland
- *Correspondence: Weiqi Fu,
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17
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Burlacot A, Dao O, Auroy P, Cuiné S, Li-Beisson Y, Peltier G. Alternative photosynthesis pathways drive the algal CO 2-concentrating mechanism. Nature 2022; 605:366-371. [PMID: 35477755 DOI: 10.1038/s41586-022-04662-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 03/18/2022] [Indexed: 12/13/2022]
Abstract
Global photosynthesis consumes ten times more CO2 than net anthropogenic emissions, and microalgae account for nearly half of this consumption1. The high efficiency of algal photosynthesis relies on a mechanism concentrating CO2 (CCM) at the catalytic site of the carboxylating enzyme RuBisCO, which enhances CO2 fixation2. Although many cellular components involved in the transport and sequestration of inorganic carbon have been identified3,4, how microalgae supply energy to concentrate CO2 against a thermodynamic gradient remains unknown4-6. Here we show that in the green alga Chlamydomonas reinhardtii, the combined action of cyclic electron flow and O2 photoreduction-which depend on PGRL1 and flavodiiron proteins, respectively-generate a low luminal pH that is essential for CCM function. We suggest that luminal protons are used downstream of thylakoid bestrophin-like transporters, probably for the conversion of bicarbonate to CO2. We further establish that an electron flow from chloroplast to mitochondria contributes to energizing non-thylakoid inorganic carbon transporters, probably by supplying ATP. We propose an integrated view of the network supplying energy to the CCM, and describe how algal cells distribute energy from photosynthesis to power different CCM processes. These results suggest a route for the transfer of a functional algal CCM to plants to improve crop productivity.
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Affiliation(s)
- Adrien Burlacot
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, France.,Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, USA
| | - Ousmane Dao
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, France
| | - Pascaline Auroy
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, France
| | - Stephan Cuiné
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, France
| | - Yonghua Li-Beisson
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, France
| | - Gilles Peltier
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Saint-Paul-lez-Durance, France.
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18
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Fei C, Wilson AT, Mangan NM, Wingreen NS, Jonikas MC. Modelling the pyrenoid-based CO 2-concentrating mechanism provides insights into its operating principles and a roadmap for its engineering into crops. NATURE PLANTS 2022; 8:583-595. [PMID: 35596080 PMCID: PMC9122830 DOI: 10.1038/s41477-022-01153-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 04/11/2022] [Indexed: 05/19/2023]
Abstract
Many eukaryotic photosynthetic organisms enhance their carbon uptake by supplying concentrated CO2 to the CO2-fixing enzyme Rubisco in an organelle called the pyrenoid. Ongoing efforts seek to engineer this pyrenoid-based CO2-concentrating mechanism (PCCM) into crops to increase yields. Here we develop a computational model for a PCCM on the basis of the postulated mechanism in the green alga Chlamydomonas reinhardtii. Our model recapitulates all Chlamydomonas PCCM-deficient mutant phenotypes and yields general biophysical principles underlying the PCCM. We show that an effective and energetically efficient PCCM requires a physical barrier to reduce pyrenoid CO2 leakage, as well as proper enzyme localization to reduce futile cycling between CO2 and HCO3-. Importantly, our model demonstrates the feasibility of a purely passive CO2 uptake strategy at air-level CO2, while active HCO3- uptake proves advantageous at lower CO2 levels. We propose a four-step engineering path to increase the rate of CO2 fixation in the plant chloroplast up to threefold at a theoretical cost of only 1.3 ATP per CO2 fixed, thereby offering a framework to guide the engineering of a PCCM into land plants.
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Affiliation(s)
- Chenyi Fei
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Alexandra T Wilson
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Niall M Mangan
- Department of Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, IL, USA.
| | - Ned S Wingreen
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.
| | - Martin C Jonikas
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
- Howard Hughes Medical Institute, Princeton University, Princeton, NJ, USA.
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19
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Yamano T, Toyokawa C, Shimamura D, Matsuoka T, Fukuzawa H. CO2-dependent migration and relocation of LCIB, a pyrenoid-peripheral protein in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2022; 188:1081-1094. [PMID: 34791500 PMCID: PMC8825250 DOI: 10.1093/plphys/kiab528] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 10/15/2021] [Indexed: 05/18/2023]
Abstract
Most microalgae overcome the difficulty of acquiring inorganic carbon (Ci) in aquatic environments by inducing a CO2-concentrating mechanism (CCM). In the green alga Chlamydomonas reinhardtii, two distinct photosynthetic acclimation states have been described under CO2-limiting conditions (low-CO2 [LC] and very low-CO2 [VLC]). LC-inducible protein B (LCIB), structurally characterized as carbonic anhydrase, localizes in the chloroplast stroma under CO2-supplied and LC conditions. In VLC conditions, it migrates to aggregate around the pyrenoid, where the CO2-fixing enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase is enriched. Although the physiological importance of LCIB localization changes in the chloroplast has been shown, factors necessary for the localization changes remain uncertain. Here, we examined the effect of pH, light availability, photosynthetic electron flow, and protein synthesis on the localization changes, along with measuring Ci concentrations. LCIB dispersed or localized in the basal region of the chloroplast stroma at 8.3-15 µM CO2, whereas LCIB migrated toward the pyrenoid at 6.5 µM CO2. Furthermore, LCIB relocated toward the pyrenoid at 2.6-3.4 µM CO2, even in cells in the dark or treated with 3-(3,4-dichlorophenyl)-1,1-dimethylurea and cycloheximide in light. In contrast, in the mutant lacking CCM1, a master regulator of CCM, LCIB remained dispersed even at 4.3 µM CO2. Meanwhile, a simultaneous expression of LCIC, an interacting protein of LCIB, induced the localization of several speckled structures at the pyrenoid periphery. These results suggest that the localization changes of LCIB require LCIC and are controlled by CO2 concentration with ∼7 µM as the boundary.
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Affiliation(s)
- Takashi Yamano
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Chihana Toyokawa
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Daisuke Shimamura
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Toshiki Matsuoka
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
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20
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Choi BY, Kim H, Shim D, Jang S, Yamaoka Y, Shin S, Yamano T, Kajikawa M, Jin E, Fukuzawa H, Lee Y. The Chlamydomonas bZIP transcription factor BLZ8 confers oxidative stress tolerance by inducing the carbon-concentrating mechanism. THE PLANT CELL 2022; 34:910-926. [PMID: 34893905 PMCID: PMC8824676 DOI: 10.1093/plcell/koab293] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 11/28/2021] [Indexed: 05/19/2023]
Abstract
Photosynthetic organisms are exposed to various environmental sources of oxidative stress. Land plants have diverse mechanisms to withstand oxidative stress, but how microalgae do so remains unclear. Here, we characterized the Chlamydomonas reinhardtii basic leucine zipper (bZIP) transcription factor BLZ8, which is highly induced by oxidative stress. Oxidative stress tolerance increased with increasing BLZ8 expression levels. BLZ8 regulated the expression of genes likely involved in the carbon-concentrating mechanism (CCM): HIGH-LIGHT ACTIVATED 3 (HLA3), CARBONIC ANHYDRASE 7 (CAH7), and CARBONIC ANHYDRASE 8 (CAH8). BLZ8 expression increased the photosynthetic affinity for inorganic carbon under alkaline stress conditions, suggesting that BLZ8 induces the CCM. BLZ8 expression also increased the photosynthetic linear electron transfer rate, reducing the excitation pressure of the photosynthetic electron transport chain and in turn suppressing reactive oxygen species (ROS) production under oxidative stress conditions. A carbonic anhydrase inhibitor, ethoxzolamide, abolished the enhanced tolerance to alkaline stress conferred by BLZ8 overexpression. BLZ8 directly regulated the expression of the three target genes and required bZIP2 as a dimerization partner in activating CAH8 and HLA3. Our results suggest that a CCM-mediated increase in the CO2 supply for photosynthesis is critical to minimize oxidative damage in microalgae, since slow gas diffusion in aqueous environments limits CO2 availability for photosynthesis, which can trigger ROS formation.
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Affiliation(s)
| | | | - Donghwan Shim
- Department of Biological Sciences, Chungnam National University, Daejeon 34134 Korea
| | - Sunghoon Jang
- Department of Life Science, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | | | - Seungjun Shin
- Department of Life Science, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Takashi Yamano
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | | | - EonSeon Jin
- Department of Life Science, Hanyang University, Seoul 133-791, South Korea
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21
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Çakirsoy I, Miyamoto T, Ohtake N. Physiology of microalgae and their application to sustainable agriculture: A mini-review. FRONTIERS IN PLANT SCIENCE 2022; 13:1005991. [PMID: 36466259 PMCID: PMC9712798 DOI: 10.3389/fpls.2022.1005991] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 10/24/2022] [Indexed: 05/13/2023]
Abstract
Concern that depletion of fertilizer feedstocks, which are a finite mineral resource, threatens agricultural sustainability has driven the exploration of sustainable methods of soil fertilization. Given that microalgae, which are unicellular photosynthetic organisms, can take up nutrients efficiently from water systems, their application in a biological wastewater purification system followed by the use of their biomass as a fertilizer alternative has attracted attention. Such applications of microalgae would contribute to the accelerated recycling of nutrients from wastewater to farmland. Many previous reports have provided information on the physiological characteristics of microalgae that support their utility. In this review, we focus on recent achievements of studies on microalgal physiology and relevant applications and outline the prospects for the contribution of microalgae to the establishment of sustainable agricultural practices.
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Affiliation(s)
- Iffet Çakirsoy
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
| | - Takuji Miyamoto
- Sakeology Center, Niigata University, Niigata, Japan
- *Correspondence: Takuji Miyamoto, ; Norikuni Ohtake,
| | - Norikuni Ohtake
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
- *Correspondence: Takuji Miyamoto, ; Norikuni Ohtake,
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22
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Neofotis P, Temple J, Tessmer OL, Bibik J, Norris N, Pollner E, Lucker B, Weraduwage SM, Withrow A, Sears B, Mogos G, Frame M, Hall D, Weissman J, Kramer DM. The induction of pyrenoid synthesis by hyperoxia and its implications for the natural diversity of photosynthetic responses in Chlamydomonas. eLife 2021; 10:67565. [PMID: 34936552 PMCID: PMC8694700 DOI: 10.7554/elife.67565] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 11/13/2021] [Indexed: 12/31/2022] Open
Abstract
In algae, it is well established that the pyrenoid, a component of the carbon-concentrating mechanism (CCM), is essential for efficient photosynthesis at low CO2. However, the signal that triggers the formation of the pyrenoid has remained elusive. Here, we show that, in Chlamydomonas reinhardtii, the pyrenoid is strongly induced by hyperoxia, even at high CO2 or bicarbonate levels. These results suggest that the pyrenoid can be induced by a common product of photosynthesis specific to low CO2 or hyperoxia. Consistent with this view, the photorespiratory by-product, H2O2, induced the pyrenoid, suggesting that it acts as a signal. Finally, we show evidence for linkages between genetic variations in hyperoxia tolerance, H2O2 signaling, and pyrenoid morphologies.
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Affiliation(s)
- Peter Neofotis
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Joshua Temple
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States.,Department of Plant Biology, Michigan State University, East Lansing, United States
| | - Oliver L Tessmer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Jacob Bibik
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Nicole Norris
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Eric Pollner
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Ben Lucker
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Sarathi M Weraduwage
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States.,Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, United States
| | - Alecia Withrow
- Center for Advanced Microscopy, Michigan State University, East Lansing, United States
| | - Barbara Sears
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Greg Mogos
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Melinda Frame
- Center for Advanced Microscopy, Michigan State University, East Lansing, United States
| | - David Hall
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
| | - Joseph Weissman
- Corporate Strategic Research, ExxonMobil, Annandale, United States
| | - David M Kramer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, United States
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23
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Rai AK, Chen T, Moroney JV. Mitochondrial carbonic anhydrases are needed for optimal photosynthesis at low CO2 levels in Chlamydomonas. PLANT PHYSIOLOGY 2021; 187:1387-1398. [PMID: 34618049 PMCID: PMC8566214 DOI: 10.1093/plphys/kiab351] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 07/05/2021] [Indexed: 05/19/2023]
Abstract
Chlamydomonas reinhardtii can grow photosynthetically using CO2 or in the dark using acetate as the carbon source. In the light in air, the CO2 concentrating mechanism (CCM) of C. reinhardtii accumulates CO2, enhancing photosynthesis. A combination of carbonic anhydrases (CAs) and bicarbonate transporters in the CCM of C. reinhardtii increases the CO2 concentration at Ribulose 1,5-bisphosphate carboxylase oxygenase (Rubisco) in the chloroplast pyrenoid. Previously, CAs important to the CCM have been found in the periplasmic space, surrounding the pyrenoid and inside the thylakoid lumen. Two almost identical mitochondrial CAs, CAH4 and CAH5, are also highly expressed when the CCM is made, but their role in the CCM is not understood. Here, we adopted an RNAi approach to reduce the expression of CAH4 and CAH5 to study their possible physiological functions. RNAi mutants with low expression of CAH4 and CAH5 had impaired rates of photosynthesis under ambient levels of CO2 (0.04% CO2 [v/v] in air). These strains were not able to grow at very low CO2 (<0.02% CO2 [v/v] in air), and their ability to accumulate inorganic carbon (Ci = CO2 + HCO3-) was reduced. At low CO2 concentrations, the CCM is needed to both deliver Ci to Rubisco and to minimize the leak of CO2 generated by respiration and photorespiration. We hypothesize that CAH4 and CAH5 in the mitochondria convert the CO2 released from respiration and photorespiration as well as the CO2 leaked from the chloroplast to HCO3- thus "recapturing" this potentially lost CO2.
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Affiliation(s)
- Ashwani K Rai
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - Timothy Chen
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - James V Moroney
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, USA
- Author for communication:
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24
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Shukshina AK, Terentyev VV. Involvement of Carbonic Anhydrase CAH3 in the Structural and Functional Stabilization of the Water-Oxidizing Complex of Photosystem II from Chlamydomonas reinhardtii. BIOCHEMISTRY (MOSCOW) 2021; 86:867-877. [PMID: 34284710 DOI: 10.1134/s0006297921070075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The involvement of carbonic anhydrases (CA) and CA activity in the functioning of photosystem II (PSII) has been studied for a long time and has been shown in many works. However, so far only for CAH3 from Chlamydomonas reinhardtii there is evidence for its association with the donor side of PSII, where the CA activity of CAH3 can influence the functioning of the water-oxidizing complex (WOC). Our results suggest that CAH3 is also involved in the organization of the native structure of WOC independently of its CA activity. It was shown that in PSII preparations from wild type (WT) the high O2-evolving activity of WOC was observed up to 100 mM NaCl in the medium and practically did not decrease with increasing incubation time with NaCl. At the same time, the WOC function in PSII preparations from CAH3-deficient mutant cia3 is significantly inhibited already at NaCl concentrations above 35 mM, reaching 50% at 100 mM NaCl and increased incubation time. It is suggested that the absence of CAH3 in PSII from cia3 causes disruption of the native structure of WOC, allowing more pronounced conformational changes of its proteins and, consequently, suppression of the WOC active center function, when the ionic strength of the medium is increased. The results of Western blot analysis indicate a more difficult removal of PsbP protein from PSII of cia3 at higher NaCl concentrations, apparently due to the changes in the intermolecular interactions between proteins of WOC in the absence of CAH3. At the same time, the values of the maximum quantum yield of PSII did not practically differ between preparations from WT and cia3, indicating no effect of CAH3 on the photoinduced electron transfer in the reaction center of PSII. The obtained results indicate the involvement of the CAH3 protein in the native organization of the WOC and, as a consequence, in the stabilization of its functional state in PSII from C. reinhardtii.
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Affiliation(s)
- Anna K Shukshina
- Institute of Basic Biological Problems, Pushchino Scientific Center for Biological Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - Vasily V Terentyev
- Institute of Basic Biological Problems, Pushchino Scientific Center for Biological Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
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25
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Santhanagopalan I, Wong R, Mathur T, Griffiths H. Orchestral manoeuvres in the light: crosstalk needed for regulation of the Chlamydomonas carbon concentration mechanism. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:4604-4624. [PMID: 33893473 PMCID: PMC8320531 DOI: 10.1093/jxb/erab169] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/19/2021] [Indexed: 05/19/2023]
Abstract
The inducible carbon concentration mechanism (CCM) in Chlamydomonas reinhardtii has been well defined from a molecular and ultrastructural perspective. Inorganic carbon transport proteins, and strategically located carbonic anhydrases deliver CO2 within the chloroplast pyrenoid matrix where Rubisco is packaged. However, there is little understanding of the fundamental signalling and sensing processes leading to CCM induction. While external CO2 limitation has been believed to be the primary cue, the coupling between energetic supply and inorganic carbon demand through regulatory feedback from light harvesting and photorespiration signals could provide the original CCM trigger. Key questions regarding the integration of these processes are addressed in this review. We consider how the chloroplast functions as a crucible for photosynthesis, importing and integrating nuclear-encoded components from the cytoplasm, and sending retrograde signals to the nucleus to regulate CCM induction. We hypothesize that induction of the CCM is associated with retrograde signals associated with photorespiration and/or light stress. We have also examined the significance of common evolutionary pressures for origins of two co-regulated processes, namely the CCM and photorespiration, in addition to identifying genes of interest involved in transcription, protein folding, and regulatory processes which are needed to fully understand the processes leading to CCM induction.
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Affiliation(s)
- Indu Santhanagopalan
- Department of Plant Sciences, Downing Street, University of Cambridge, Cambridge, UK
| | - Rachel Wong
- Department of Plant Sciences, Downing Street, University of Cambridge, Cambridge, UK
| | - Tanya Mathur
- Department of Plant Sciences, Downing Street, University of Cambridge, Cambridge, UK
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26
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Horiguchi G, Matsumoto K, Nemoto K, Inokuchi M, Hirotsu N. Transition From Proto-Kranz-Type Photosynthesis to HCO 3 - Use Photosynthesis in the Amphibious Plant Hygrophila polysperma. FRONTIERS IN PLANT SCIENCE 2021; 12:675507. [PMID: 34220895 PMCID: PMC8242947 DOI: 10.3389/fpls.2021.675507] [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: 03/03/2021] [Accepted: 04/26/2021] [Indexed: 06/13/2023]
Abstract
Hygrophila polysperma is a heterophyllous amphibious plant. The growth of H. polysperma in submerged conditions is challenging due to the low CO2 environment, increased resistance to gas diffusion, and bicarbonate ion (HCO3 -) being the dominant dissolved inorganic carbon source. The submerged leaves of H. polysperma have significantly higher rates of underwater photosynthesis compared with the terrestrial leaves. 4,4'-Diisothiocyanatostilbene-2,2'-disulfonate (DIDS), an anion exchanger protein inhibitor, and ethoxyzolamide (EZ), an inhibitor of internal carbonic anhydrase, repressed underwater photosynthesis by the submerged leaves. These results suggested that H. polysperma acclimates to the submerged condition by using HCO3 - for photosynthesis. H. polysperma transports HCO3 - into the leaf by a DIDS-sensitive HCO3 - transporter and converted to CO2 by carbonic anhydrase. Additionally, proteome analysis revealed that submerged leaves accumulated fewer proteins associated with C4 photosynthesis compared with terrestrial leaves. This finding suggested that H. polysperma is capable of C4 and C3 photosynthesis in the terrestrial and submerged leaves, respectively. The ratio of phosphoenol pyruvate carboxylase to ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) in the submerged leaves was less than that in the terrestrial leaves. Upon anatomical observation, the terrestrial leaves exhibited a phenotype similar to the Kranz anatomy found among C4 plants; however, chloroplasts in the bundle sheath cells were not located adjacent to the vascular bundles, and the typical Kranz anatomy was absent in submerged leaves. These results suggest that H. polysperma performs proto-Kranz type photosynthesis in a terrestrial environment and shifts from a proto-Kranz type in terrestrial leaves to a HCO3 - use photosynthesis in the submerged environments.
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Affiliation(s)
- Genki Horiguchi
- Graduate School of Life Sciences, Toyo University, Gunma, Japan
| | | | - Kyosuke Nemoto
- Graduate School of Life Sciences, Toyo University, Gunma, Japan
| | - Mayu Inokuchi
- Faculty of Life Sciences, Toyo University, Gunma, Japan
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Naoki Hirotsu
- Graduate School of Life Sciences, Toyo University, Gunma, Japan
- Faculty of Life Sciences, Toyo University, Gunma, Japan
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27
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Tsuji Y, Kusi-Appiah G, Kozai N, Fukuda Y, Yamano T, Fukuzawa H. Characterization of a CO 2-Concentrating Mechanism with Low Sodium Dependency in the Centric Diatom Chaetoceros gracilis. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2021; 23:456-462. [PMID: 34109463 DOI: 10.1007/s10126-021-10037-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 05/13/2021] [Indexed: 06/12/2023]
Abstract
Microalgae induce a CO2-concentrating mechanism (CCM) to overcome CO2-limiting stress in aquatic environments by coordinating inorganic carbon (Ci) transporters and carbonic anhydrases (CAs). Two mechanisms have been suggested to facilitate Ci uptake from aqueous media: Na+-dependent HCO3- uptake by solute carrier (SLC) family transporters and accelerated dehydration of HCO3- to CO2 by external CA in model diatoms. However, studies on ecologically and industrially important diatoms including Chaetoceros gracilis, a common food source in aquacultures, are still limited. Here, we characterized the CCM of C. gracilis using inhibitors and growth dependency on Na+ and CO2. Addition of a membrane-impermeable SLC inhibitor, 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS), or the transient removal of Na+ from the culture medium did not impair photosynthetic affinity for Ci in CO2-limiting stress conditions, but addition of a membrane-impermeable CA inhibitor, acetazolamide, decreased Ci affinity to one-third of control cultures. In culture medium containing 0.23 mM Na+ C. gracilis grew photoautotrophically by aeration with air containing 5% CO2, but not with the air containing 0.04% CO2. These results suggested that C. gracilis utilizes external CAs in its CCM to elevate photosynthetic affinity for Ci rather than plasma-membrane SLC family transporters. In addition, it is possible that low level of Na+ may support the CCM in processes other than Ci-uptake at the plasma membrane specifically in CO2-limiting conditions. Our findings provide insights into the diversity of CCMs among diatoms as well as basic information to optimize culture conditions for industrial applications.
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Affiliation(s)
- Yoshinori Tsuji
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | | | - Noriko Kozai
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Yuri Fukuda
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Takashi Yamano
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan.
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28
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Synthetic Biology Approaches To Enhance Microalgal Productivity. Trends Biotechnol 2021; 39:1019-1036. [PMID: 33541719 DOI: 10.1016/j.tibtech.2020.12.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/22/2020] [Accepted: 12/29/2020] [Indexed: 12/15/2022]
Abstract
The major bottleneck in commercializing biofuels and other commodities produced by microalgae is the high cost associated with phototrophic cultivation. Improving microalgal productivities could be a solution to this problem. Synthetic biology methods have recently been used to engineer the downstream production pathways in several microalgal strains. However, engineering upstream photosynthetic and carbon fixation metabolism to enhance growth, productivity, and yield has barely been explored in microalgae. We describe strategies to improve the generation of reducing power from light, as well as to improve the assimilation of CO2 by either the native Calvin cycle or synthetic alternatives. Overall, we are optimistic that recent technological advances will prompt long-awaited breakthroughs in microalgal research.
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29
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Atkinson N, Mao Y, Chan KX, McCormick AJ. Condensation of Rubisco into a proto-pyrenoid in higher plant chloroplasts. Nat Commun 2020; 11:6303. [PMID: 33298923 PMCID: PMC7726157 DOI: 10.1038/s41467-020-20132-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 11/12/2020] [Indexed: 12/20/2022] Open
Abstract
Photosynthetic CO2 fixation in plants is limited by the inefficiency of the CO2-assimilating enzyme Rubisco. In most eukaryotic algae, Rubisco aggregates within a microcompartment known as the pyrenoid, in association with a CO2-concentrating mechanism that improves photosynthetic operating efficiency under conditions of low inorganic carbon. Recent work has shown that the pyrenoid matrix is a phase-separated, liquid-like condensate. In the alga Chlamydomonas reinhardtii, condensation is mediated by two components: Rubisco and the linker protein EPYC1 (Essential Pyrenoid Component 1). Here, we show that expression of mature EPYC1 and a plant-algal hybrid Rubisco leads to spontaneous condensation of Rubisco into a single phase-separated compartment in Arabidopsis chloroplasts, with liquid-like properties similar to a pyrenoid matrix. This work represents a significant initial step towards enhancing photosynthesis in higher plants by introducing an algal CO2-concentrating mechanism, which is predicted to significantly increase the efficiency of photosynthetic CO2 uptake.
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Affiliation(s)
- Nicky Atkinson
- SynthSys & Institute of Molecular Plant Sciences, School of Biological Sciences, King's Buildings, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Yuwei Mao
- SynthSys & Institute of Molecular Plant Sciences, School of Biological Sciences, King's Buildings, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Kher Xing Chan
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 Gregory Drive, Urbana, IL, 61801, USA
| | - Alistair J McCormick
- SynthSys & Institute of Molecular Plant Sciences, School of Biological Sciences, King's Buildings, University of Edinburgh, Edinburgh, EH9 3BF, UK.
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30
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Chlamydomonas reinhardtii tubulin-gene disruptants for efficient isolation of strains bearing tubulin mutations. PLoS One 2020; 15:e0242694. [PMID: 33227038 PMCID: PMC7682851 DOI: 10.1371/journal.pone.0242694] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 11/08/2020] [Indexed: 11/24/2022] Open
Abstract
The single-cell green alga Chlamydomonas reinhardtii possesses two α-tubulin genes (tua1 and tua2) and two β-tubulin genes (tub1 and tub2), with the two genes in each pair encoding identical amino acid sequences. Here, we screened an insertional library to establish eight disruptants with defective tua2, tub1, or tub2 expression. Most of the disruptants did not exhibit major defects in cell growth, flagellar length, or flagellar regeneration after amputation. Because few tubulin mutants of C. reinhardtii have been reported to date, we then used our disruptants, together with a tua1 disruptant obtained from the Chlamydomonas Library Project (CLiP), to isolate tubulin-mutants resistant to the anti-tubulin agents propyzamide (pronamide) or oryzalin. As a result of several trials, we obtained 8 strains bearing 7 different α-tubulin mutations and 12 strains bearing 7 different β-tubulin mutations. One of the mutations is at a residue similar to that of a mutation site known to confer drug resistance in human cancer cells. Some strains had the same amino acid substitutions as those reported previously in C. reinhardtii; however, the mutants with single tubulin genes showed slightly stronger drug-resistance than the previous mutants that express the mutated tubulin in addition to the wild-type tubulin. Such increased drug-resistance may have facilitated sensitive detection of tubulin mutation. Single-tubulin-gene disruptants are thus an efficient background of generating tubulin mutants for the study of the structure–function relationship of tubulin.
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31
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Elucidation and genetic intervention of CO2 concentration mechanism in Chlamydomonas reinhardtii for increased plant primary productivity. J Biosci 2020. [DOI: 10.1007/s12038-020-00080-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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32
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Kumar G, Shekh A, Jakhu S, Sharma Y, Kapoor R, Sharma TR. Bioengineering of Microalgae: Recent Advances, Perspectives, and Regulatory Challenges for Industrial Application. Front Bioeng Biotechnol 2020; 8:914. [PMID: 33014997 PMCID: PMC7494788 DOI: 10.3389/fbioe.2020.00914] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/15/2020] [Indexed: 01/14/2023] Open
Abstract
Microalgae, due to their complex metabolic capacity, are being continuously explored for nutraceuticals, pharmaceuticals, and other industrially important bioactives. However, suboptimal yield and productivity of the bioactive of interest in local and robust wild-type strains are of perennial concerns for their industrial applications. To overcome such limitations, strain improvement through genetic engineering could play a decisive role. Though the advanced tools for genetic engineering have emerged at a greater pace, they still remain underused for microalgae as compared to other microorganisms. Pertaining to this, we reviewed the progress made so far in the development of molecular tools and techniques, and their deployment for microalgae strain improvement through genetic engineering. The recent availability of genome sequences and other omics datasets form diverse microalgae species have remarkable potential to guide strategic momentum in microalgae strain improvement program. This review focuses on the recent and significant improvements in the omics resources, mutant libraries, and high throughput screening methodologies helpful to augment research in the model and non-model microalgae. Authors have also summarized the case studies on genetically engineered microalgae and highlight the opportunities and challenges that are emerging from the current progress in the application of genome-editing to facilitate microalgal strain improvement. Toward the end, the regulatory and biosafety issues in the use of genetically engineered microalgae in commercial applications are described.
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Affiliation(s)
- Gulshan Kumar
- Agricultural Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), Sahibzada Ajit Singh Nagar, India
| | - Ajam Shekh
- Plant Cell Biotechnology Department, CSIR-Central Food Technological Research Institute (CFTRI), Mysuru, India
| | - Sunaina Jakhu
- Agricultural Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), Sahibzada Ajit Singh Nagar, India
| | - Yogesh Sharma
- Agricultural Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), Sahibzada Ajit Singh Nagar, India
| | - Ritu Kapoor
- Agricultural Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), Sahibzada Ajit Singh Nagar, India
| | - Tilak Raj Sharma
- Division of Crop Science, Indian Council of Agricultural Research, New Delhi, India
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33
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Goudet MMM, Orr DJ, Melkonian M, Müller KH, Meyer MT, Carmo-Silva E, Griffiths H. Rubisco and carbon-concentrating mechanism co-evolution across chlorophyte and streptophyte green algae. THE NEW PHYTOLOGIST 2020; 227:810-823. [PMID: 32249430 DOI: 10.1111/nph.16577] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 03/23/2020] [Indexed: 05/19/2023]
Abstract
Green algae expressing a carbon-concentrating mechanism (CCM) are usually associated with a Rubisco-containing micro-compartment, the pyrenoid. A link between the small subunit (SSU) of Rubisco and pyrenoid formation in Chlamydomonas reinhardtii has previously suggested that specific RbcS residues could explain pyrenoid occurrence in green algae. A phylogeny of RbcS was used to compare the protein sequence and CCM distribution across the green algae and positive selection in RbcS was estimated. For six streptophyte algae, Rubisco catalytic properties, affinity for CO2 uptake (K0.5 ), carbon isotope discrimination (δ13 C) and pyrenoid morphology were compared. The length of the βA-βB loop in RbcS provided a phylogenetic marker discriminating chlorophyte from streptophyte green algae. Rubisco kinetic properties in streptophyte algae have responded to the extent of inducible CCM activity, as indicated by changes in inorganic carbon uptake affinity, δ13 C and pyrenoid ultrastructure between high and low CO2 conditions for growth. We conclude that the Rubisco catalytic properties found in streptophyte algae have coevolved and reflect the strength of any CCM or degree of pyrenoid leakiness, and limitations to inorganic carbon in the aquatic habitat, whereas Rubisco in extant land plants reflects more recent selective pressures associated with improved diffusive supply of the terrestrial environment.
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Affiliation(s)
- Myriam M M Goudet
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | - Douglas J Orr
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK
| | - Michael Melkonian
- Institute for Plant Sciences, Department of Biological Sciences, University of Cologne, 50674, Cologne, Germany
- Central Collection of Algal Cultures, Faculty of Biology, University of Duisburg-Essen, 45141, Essen, Germany
| | - Karin H Müller
- Cambridge Advanced Imaging Centre, University of Cambridge, Cambridge, CB2 3DY, UK
| | - Moritz T Meyer
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA
| | | | - Howard Griffiths
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
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34
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Kareya MS, Mariam I, Shaikh KM, Nesamma AA, Jutur PP. Photosynthetic Carbon Partitioning and Metabolic Regulation in Response to Very-Low and High CO 2 in Microchloropsis gaditana NIES 2587. FRONTIERS IN PLANT SCIENCE 2020; 11:981. [PMID: 32719702 PMCID: PMC7348049 DOI: 10.3389/fpls.2020.00981] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 06/16/2020] [Indexed: 05/06/2023]
Abstract
Photosynthetic organisms fix inorganic carbon through carbon capture machinery (CCM) that regulates the assimilation and accumulation of carbon around ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). However, few constraints that govern the central carbon metabolism are regulated by the carbon capture and partitioning machinery. In order to divert the cellular metabolism toward lipids and/or biorenewables it is important to investigate and understand the molecular mechanisms of the CO2-driven carbon partitioning. In this context, strategies for enhancement of CO2 fixation which will increase the overall biomass and lipid yields, can provide clues on understanding the carbon assimilation pathway, and may lead to new targets for genetic engineering in microalgae. In the present study, we have focused on the physiological and metabolomic response occurring within marine oleaginous microalgae Microchloropsis gaditana NIES 2587, under the influence of very-low CO2 (VLC; 300 ppm, or 0.03%) and high CO2 (HC; 30,000 ppm, or 3% v/v). Our results demonstrate that HC supplementation in M. gaditana channelizes the carbon flux toward the production of long chain polyunsaturated fatty acids (LC-PUFAs) and also increases the overall biomass productivities (up to 2.0 fold). Also, the qualitative metabolomics has identified nearly 31 essential metabolites, among which there is a significant fold change observed in accumulation of sugars and alcohols such as galactose and phytol in VLC as compared to HC. In conclusion, our focus is to understand the entire carbon partitioning and metabolic regulation within these photosynthetic cell factories, which will be further evaluated through multiomics approach for enhanced productivities of biomass, biofuels, and bioproducts (B3).
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Affiliation(s)
| | | | | | | | - Pannaga Pavan Jutur
- Omics of Algae Group, Industrial Biotechnology, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
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35
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Kono A, Chou TH, Radhakrishnan A, Bolla JR, Sankar K, Shome S, Su CC, Jernigan RL, Robinson CV, Yu EW, Spalding MH. Structure and function of LCI1: a plasma membrane CO 2 channel in the Chlamydomonas CO 2 concentrating mechanism. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 102:1107-1126. [PMID: 32168387 PMCID: PMC7305984 DOI: 10.1111/tpj.14745] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 01/18/2020] [Accepted: 02/20/2020] [Indexed: 05/19/2023]
Abstract
Microalgae and cyanobacteria contribute roughly half of the global photosynthetic carbon assimilation. Faced with limited access to CO2 in aquatic environments, which can vary daily or hourly, these microorganisms have evolved use of an efficient CO2 concentrating mechanism (CCM) to accumulate high internal concentrations of inorganic carbon (Ci ) to maintain photosynthetic performance. For eukaryotic algae, a combination of molecular, genetic and physiological studies using the model organism Chlamydomonas reinhardtii, have revealed the function and molecular characteristics of many CCM components, including active Ci uptake systems. Fundamental to eukaryotic Ci uptake systems are Ci transporters/channels located in membranes of various cell compartments, which together facilitate the movement of Ci from the environment into the chloroplast, where primary CO2 assimilation occurs. Two putative plasma membrane Ci transporters, HLA3 and LCI1, are reportedly involved in active Ci uptake. Based on previous studies, HLA3 clearly plays a meaningful role in HCO3- transport, but the function of LCI1 has not yet been thoroughly investigated so remains somewhat obscure. Here we report a crystal structure of the full-length LCI1 membrane protein to reveal LCI1 structural characteristics, as well as in vivo physiological studies in an LCI1 loss-of-function mutant to reveal the Ci species preference for LCI1. Together, these new studies demonstrate LCI1 plays an important role in active CO2 uptake and that LCI1 likely functions as a plasma membrane CO2 channel, possibly a gated channel.
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Affiliation(s)
- Alfredo Kono
- Department of Genetics, Developmental and Cell Biology, Iowa State University, Ames, IA 50011, USA
| | - Tsung-Han Chou
- Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA
- Present address: WM Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Abhijith Radhakrishnan
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA
- Present address: Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Jani Reddy Bolla
- Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, South Park Road, OX1 3QZ, UK
| | - Kannan Sankar
- Bioinformatics and Computational Biology Interdepartmental Graduate Program, Iowa State University, Ames, IA 50011, USA
| | - Sayane Shome
- Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Chih-Chia Su
- Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA
- Present address: Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106
| | - Robert L. Jernigan
- Bioinformatics and Computational Biology Interdepartmental Graduate Program, Iowa State University, Ames, IA 50011, USA
- Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Carol V. Robinson
- Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, South Park Road, OX1 3QZ, UK
| | - Edward W. Yu
- Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA
- Present address: Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106
| | - Martin H. Spalding
- Department of Genetics, Developmental and Cell Biology, Iowa State University, Ames, IA 50011, USA
- To whom correspondence should be addressed.
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Kono A, Spalding MH. LCI1, a Chlamydomonas reinhardtii plasma membrane protein, functions in active CO 2 uptake under low CO 2. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 102:1127-1141. [PMID: 32248584 DOI: 10.1111/tpj.14761] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 01/16/2020] [Accepted: 03/18/2020] [Indexed: 05/11/2023]
Abstract
In response to high CO2 environmental variability, green algae, such as Chlamydomonas reinhardtii, have evolved multiple physiological states dictated by external CO2 concentration. Genetic and physiological studies demonstrated that at least three CO2 physiological states, a high CO2 (0.5-5% CO2 ), a low CO2 (0.03-0.4% CO2 ) and a very low CO2 (< 0.02% CO2 ) state, exist in Chlamydomonas. To acclimate in the low and very low CO2 states, Chlamydomonas induces a sophisticated strategy known as a CO2 -concentrating mechanism (CCM) that enables proliferation and survival in these unfavorable CO2 environments. Active uptake of Ci from the environment is a fundamental aspect in the Chlamydomonas CCM, and consists of CO2 and HCO3- uptake systems that play distinct roles in low and very low CO2 acclimation states. LCI1, a putative plasma membrane Ci transporter, has been linked through conditional overexpression to active Ci uptake. However, both the role of LCI1 in various CO2 acclimation states and the species of Ci , HCO3- or CO2 , that LCI1 transports remain obscure. Here we report the impact of an LCI1 loss-of-function mutant on growth and photosynthesis in different genetic backgrounds at multiple pH values. These studies show that LCI1 appears to be associated with active CO2 uptake in low CO2 , especially above air-level CO2 , and that any LCI1 role in very low CO2 is minimal.
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Affiliation(s)
- Alfredo Kono
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, 50011, USA
| | - Martin H Spalding
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, 50011, USA
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Hennacy JH, Jonikas MC. Prospects for Engineering Biophysical CO 2 Concentrating Mechanisms into Land Plants to Enhance Yields. ANNUAL REVIEW OF PLANT BIOLOGY 2020; 71:461-485. [PMID: 32151155 PMCID: PMC7845915 DOI: 10.1146/annurev-arplant-081519-040100] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Although cyanobacteria and algae represent a small fraction of the biomass of all primary producers, their photosynthetic activity accounts for roughly half of the daily CO2 fixation that occurs on Earth. These microorganisms are able to accomplish this feat by enhancing the activity of the CO2-fixing enzyme Rubisco using biophysical CO2 concentrating mechanisms (CCMs). Biophysical CCMs operate by concentrating bicarbonate and converting it into CO2 in a compartment that houses Rubisco (in contrast with other CCMs that concentrate CO2 via an organic intermediate, such as malate in the case of C4 CCMs). This activity provides Rubisco with a high concentration of its substrate, thereby increasing its reaction rate. The genetic engineering of a biophysical CCM into land plants is being pursued as a strategy to increase crop yields. This review focuses on the progress toward understanding the molecular components of cyanobacterial and algal CCMs, as well as recent advances toward engineering these components into land plants.
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Affiliation(s)
- Jessica H Hennacy
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA; ,
| | - Martin C Jonikas
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA; ,
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Toyokawa C, Yamano T, Fukuzawa H. Pyrenoid Starch Sheath Is Required for LCIB Localization and the CO 2-Concentrating Mechanism in Green Algae. PLANT PHYSIOLOGY 2020; 182:1883-1893. [PMID: 32041908 PMCID: PMC7140920 DOI: 10.1104/pp.19.01587] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 01/24/2020] [Indexed: 05/09/2023]
Abstract
Aquatic photosynthetic organisms induce a CO2-concentrating mechanism (CCM) to overcome the difficulty of acquiring inorganic carbon under CO2-limiting conditions. As part of the CCM, the CO2-fixing enzyme Rubisco is enriched in the pyrenoid located in the chloroplast, and, in many green algae, several thick starch plates surround the pyrenoid to form a starch sheath. In Chlamydomonas reinhardtii, low-CO2-inducible protein B (LCIB), which is an essential factor for the CCM, displays altered cellular localization in response to a decrease in environmental CO2 concentration, moving from dispersed throughout the chloroplast stroma to around the pyrenoid. However, the mechanism behind LCIB migration remains poorly understood. Here, we report the characteristics of an Isoamylase1-less mutant (4-D1), which shows aberrant LCIB localization and starch sheath formation. Under very-low-CO2 conditions, 4-D1 showed retarded growth, lower photosynthetic affinities against inorganic carbon, and a decreased accumulation level of the HCO3 - transporter HLA3. The aberrant localization of LCIB was also observed in another starch-sheathless mutant sta11-1, but not in sta2-1, which possesses a thinned starch sheath. These results suggest that the starch sheath around the pyrenoid is required for the correct localization of LCIB and for the operation of CCM.
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Affiliation(s)
- Chihana Toyokawa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Takashi Yamano
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
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Ng I, Keskin BB, Tan S. A Critical Review of Genome Editing and Synthetic Biology Applications in Metabolic Engineering of Microalgae and Cyanobacteria. Biotechnol J 2020; 15:e1900228. [DOI: 10.1002/biot.201900228] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 02/07/2020] [Indexed: 12/13/2022]
Affiliation(s)
- I‐Son Ng
- Department of Chemical EngineeringNational Cheng Kung University Tainan 701 Taiwan
| | - Batuhan Birol Keskin
- Department of Chemical EngineeringNational Cheng Kung University Tainan 701 Taiwan
| | - Shih‐I Tan
- Department of Chemical EngineeringNational Cheng Kung University Tainan 701 Taiwan
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Falciatore A, Jaubert M, Bouly JP, Bailleul B, Mock T. Diatom Molecular Research Comes of Age: Model Species for Studying Phytoplankton Biology and Diversity. THE PLANT CELL 2020; 32:547-572. [PMID: 31852772 PMCID: PMC7054031 DOI: 10.1105/tpc.19.00158] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 10/18/2019] [Accepted: 12/13/2019] [Indexed: 05/08/2023]
Abstract
Diatoms are the world's most diverse group of algae, comprising at least 100,000 species. Contributing ∼20% of annual global carbon fixation, they underpin major aquatic food webs and drive global biogeochemical cycles. Over the past two decades, Thalassiosira pseudonana and Phaeodactylum tricornutum have become the most important model systems for diatom molecular research, ranging from cell biology to ecophysiology, due to their rapid growth rates, small genomes, and the cumulative wealth of associated genetic resources. To explore the evolutionary divergence of diatoms, additional model species are emerging, such as Fragilariopsis cylindrus and Pseudo-nitzschia multistriata Here, we describe how functional genomics and reverse genetics have contributed to our understanding of this important class of microalgae in the context of evolution, cell biology, and metabolic adaptations. Our review will also highlight promising areas of investigation into the diversity of these photosynthetic organisms, including the discovery of new molecular pathways governing the life of secondary plastid-bearing organisms in aquatic environments.
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Affiliation(s)
- Angela Falciatore
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005 Paris, France
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR7238 Sorbonne Université, 75005 Paris, France
| | - Marianne Jaubert
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005 Paris, France
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR7238 Sorbonne Université, 75005 Paris, France
| | - Jean-Pierre Bouly
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005 Paris, France
- Institut de Biologie Paris-Seine, Laboratory of Computational and Quantitative Biology, UMR7238 Sorbonne Université, 75005 Paris, France
| | - Benjamin Bailleul
- Institut de Biologie Physico-Chimique, Laboratory of Chloroplast Biology and Light Sensing in Microalgae, UMR7141 Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, 75005 Paris, France
| | - Thomas Mock
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
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Vikramathithan J, Hwangbo K, Lim JM, Lim KM, Kang DY, Park YI, Jeong WJ. Overexpression of Chlamydomonas reinhardtii LCIA (CrLCIA) gene increases growth of Nannochloropsis salina CCMP1776. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.101807] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Jang S, Kong F, Lee J, Choi BY, Wang P, Gao P, Yamano T, Fukuzawa H, Kang BH, Lee Y. CrABCA2 Facilitates Triacylglycerol Accumulation in Chlamydomonas reinhardtii under Nitrogen Starvation. Mol Cells 2020; 43:48-57. [PMID: 31910336 PMCID: PMC6999713 DOI: 10.14348/molcells.2019.0262] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 11/30/2019] [Accepted: 12/02/2019] [Indexed: 11/27/2022] Open
Abstract
The microalga Chlamydomonas reinhardtii accumulates triacylglycerols (TAGs) in lipid droplets under stress conditions, such as nitrogen starvation. TAG biosynthesis occurs mainly at the endoplasmic reticulum (ER) and requires fatty acid (FA) substrates supplied from chloroplasts. How FAs are transferred from chloroplast to ER in microalgae was unknown. We previously reported that an Arabidopsis thaliana ATP-binding cassette (ABC) transporter, AtABCA9, facilitates FA transport at the ER during seed development. Here we identified a gene homologous to AtABCA9 in the C. reinhardtii genome, which we named CrABCA2. Under nitrogen deprivation conditions, CrABCA2 expression was upregulated, and the CrABCA2 protein level also increased. CrABCA2 knockdown lines accumulated less TAGs and CrABCA2 overexpression lines accumulated more TAGs than their untransformed parental lines. Transmission electron microscopy showed that CrABCA2 was localized in swollen ER. These results suggest that CrABCA2 transports substrates for TAG biosynthesis to the ER during nitrogen starvation . Our study provides a potential tool for increasing lipid production in microalgae.
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Affiliation(s)
- Sunghoon Jang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673,
Korea
| | - Fantao Kong
- School of Bioengineering, Dalian University of Technology, Dalian 116024,
China
| | - Jihyeon Lee
- Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 37673,
Korea
| | - Bae Young Choi
- Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 37673,
Korea
| | - Pengfei Wang
- Cellular and Molecular Biology Program, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, New Territories, Hong Kong 999077,
China
| | - Peng Gao
- Cellular and Molecular Biology Program, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, New Territories, Hong Kong 999077,
China
| | - Takashi Yamano
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502,
Japan
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502,
Japan
| | - Byung-Ho Kang
- Cellular and Molecular Biology Program, State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, New Territories, Hong Kong 999077,
China
| | - Youngsook Lee
- Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 37673,
Korea
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Hidayati NA, Yamada‐Oshima Y, Iwai M, Yamano T, Kajikawa M, Sakurai N, Suda K, Sesoko K, Hori K, Obayashi T, Shimojima M, Fukuzawa H, Ohta H. Lipid remodeling regulator 1 (LRL1) is differently involved in the phosphorus-depletion response from PSR1 in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:610-626. [PMID: 31350858 PMCID: PMC6899820 DOI: 10.1111/tpj.14473] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/03/2019] [Accepted: 07/09/2019] [Indexed: 05/05/2023]
Abstract
The elucidation of lipid metabolism in microalgae has attracted broad interest, as their storage lipid, triacylglycerol (TAG), can be readily converted into biofuel via transesterification. TAG accumulates in the form of oil droplets, especially when cells undergo nutrient deprivation, such as for nitrogen (N), phosphorus (P), or sulfur (S). TAG biosynthesis under N-deprivation has been comprehensively studied in the model microalga Chlamydomonas reinhardtii, during which TAG accumulates dramatically. However, the resulting rapid breakdown of chlorophyll restricts overall oil yield productivity and causes cessation of cell growth. In contrast, P-deprivation results in oil accumulation without disrupting chloroplast integrity. We used a reverse genetics approach based on co-expression analysis to identify a transcription factor (TF) that is upregulated under P-depleted conditions. Transcriptomic analysis revealed that the mutants showed repression of genes typically associated with lipid remodeling under P-depleted conditions, such as sulfoquinovosyl diacylglycerol 2 (SQD2), diacylglycerol acyltransferase (DGTT1), and major lipid droplet protein (MLDP). As accumulation of sulfoquinovosyl diacylglycerol and TAG were suppressed in P-depleted mutants, we designated the protein as lipid remodeling regulator 1 (LRL1). LRL1 mutants showed slower growth under P-depletion. Moreover, cell size in the mutant was significantly reduced, and TAG and starch accumulation per cell were decreased. Transcriptomic analysis also suggested the repression of several genes typically upregulated in adaptation to P-depletion that are associated with the cell cycle and P and lipid metabolism. Thus, our analysis of LRL1 provides insights into P-allocation and lipid remodeling under P-depleted conditions in C. reinhardtii. OPEN RESEARCH BADGES: This article has earned an Open Data Badge for making publicly available the digitally-shareable data necessary to reproduce the reported results. The sequencing data were made publicly available under the BioProject Accession number PRJDB6733 and an accession number LC488724 at the DNA Data Bank of Japan (DDBJ). The data is available at https://trace.ddbj.nig.ac.jp/BPSearch/bioproject?acc=PRJDB6733; http://getentry.ddbj.nig.ac.jp/getentry/na/LC488724. The metabolome data were made publicly available and can be accessed at http://metabolonote.kazusa.or.jp/SE195:/; http://webs2.kazusa.or.jp/data/nur/.
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Affiliation(s)
- Nur A. Hidayati
- Graduate School of Bioscience and BiotechnologyTokyo Institute of Technology4259‐B‐65 Nagatsuta‐cho, Midori‐kuYokohama226‐8501Japan
| | - Yui Yamada‐Oshima
- Graduate School of Bioscience and BiotechnologyTokyo Institute of Technology4259‐B‐65 Nagatsuta‐cho, Midori‐kuYokohama226‐8501Japan
| | - Masako Iwai
- School of Life Science and TechnologyTokyo Institute of Technology4259‐B‐65 Nagatsuta‐cho, Midori‐kuYokohama226‐8501Japan
| | - Takashi Yamano
- Graduate School of BiostudiesKyoto UniversityKyoto606‐8502Japan
| | | | - Nozomu Sakurai
- Technology DevelopmentKazusa DNA Research InstituteKazusa‐kamatari 2‐6‐7KisarazuChiba292‐0818Japan
- Present address:
National Institute of Genetics Bioinformation & DDBJ Center1111 YataMishimaShizuoka411‐8540Japan
| | - Kunihiro Suda
- Technology DevelopmentKazusa DNA Research InstituteKazusa‐kamatari 2‐6‐7KisarazuChiba292‐0818Japan
| | - Kanami Sesoko
- School of Life Science and TechnologyTokyo Institute of Technology4259‐B‐65 Nagatsuta‐cho, Midori‐kuYokohama226‐8501Japan
| | - Koichi Hori
- School of Life Science and TechnologyTokyo Institute of Technology4259‐B‐65 Nagatsuta‐cho, Midori‐kuYokohama226‐8501Japan
| | - Takeshi Obayashi
- Graduate School of Information SciencesTohoku University6‐3‐09, Aramaki‐Aza‐Aoba, Aoba‐kuSendai980‐8679Japan
| | - Mie Shimojima
- School of Life Science and TechnologyTokyo Institute of Technology4259‐B‐65 Nagatsuta‐cho, Midori‐kuYokohama226‐8501Japan
| | - Hideya Fukuzawa
- Graduate School of BiostudiesKyoto UniversityKyoto606‐8502Japan
| | - Hiroyuki Ohta
- School of Life Science and TechnologyTokyo Institute of Technology4259‐B‐65 Nagatsuta‐cho, Midori‐kuYokohama226‐8501Japan
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Atkinson N, Velanis CN, Wunder T, Clarke DJ, Mueller-Cajar O, McCormick AJ. The pyrenoidal linker protein EPYC1 phase separates with hybrid Arabidopsis-Chlamydomonas Rubisco through interactions with the algal Rubisco small subunit. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:5271-5285. [PMID: 31504763 PMCID: PMC6793452 DOI: 10.1093/jxb/erz275] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 06/13/2019] [Indexed: 05/21/2023]
Abstract
Photosynthetic efficiencies in plants are restricted by the CO2-fixing enzyme Rubisco but could be enhanced by introducing a CO2-concentrating mechanism (CCM) from green algae, such as Chlamydomonas reinhardtii (hereafter Chlamydomonas). A key feature of the algal CCM is aggregation of Rubisco in the pyrenoid, a liquid-like organelle in the chloroplast. Here we have used a yeast two-hybrid system and higher plants to investigate the protein-protein interaction between Rubisco and essential pyrenoid component 1 (EPYC1), a linker protein required for Rubisco aggregation. We showed that EPYC1 interacts with the small subunit of Rubisco (SSU) from Chlamydomonas and that EPYC1 has at least five SSU interaction sites. Interaction is crucially dependent on the two surface-exposed α-helices of the Chlamydomonas SSU. EPYC1 could be localized to the chloroplast in higher plants and was not detrimental to growth when expressed stably in Arabidopsis with or without a Chlamydomonas SSU. Although EPYC1 interacted with Rubisco in planta, EPYC1 was a target for proteolytic degradation. Plants expressing EPYC1 did not show obvious evidence of Rubisco aggregation. Nevertheless, hybrid Arabidopsis Rubisco containing the Chlamydomonas SSU could phase separate into liquid droplets with purified EPYC1 in vitro, providing the first evidence of pyrenoid-like aggregation for Rubisco derived from a higher plant.
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Affiliation(s)
- Nicky Atkinson
- SynthSys and Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Christos N Velanis
- SynthSys and Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Tobias Wunder
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - David J Clarke
- School of Chemistry, University of Edinburgh, Edinburgh, UK
| | - Oliver Mueller-Cajar
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Alistair J McCormick
- SynthSys and Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
- Correspondence:
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Mukherjee A, Lau CS, Walker CE, Rai AK, Prejean CI, Yates G, Emrich-Mills T, Lemoine SG, Vinyard DJ, Mackinder LCM, Moroney JV. Thylakoid localized bestrophin-like proteins are essential for the CO 2 concentrating mechanism of Chlamydomonas reinhardtii. Proc Natl Acad Sci U S A 2019; 116:16915-16920. [PMID: 31391312 DOI: 10.1073/pnas.190970611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/19/2023] Open
Abstract
The green alga Chlamydomonas reinhardtii possesses a CO2 concentrating mechanism (CCM) that helps in successful acclimation to low CO2 conditions. Current models of the CCM postulate that a series of ion transporters bring HCO3- from outside the cell to the thylakoid lumen, where the carbonic anhydrase 3 (CAH3) dehydrates accumulated HCO3- to CO2, raising the CO2 concentration for Ribulose bisphosphate carboxylase/oxygenase (Rubisco). Previously, HCO3- transporters have been identified at both the plasma membrane and the chloroplast envelope, but the transporter thought to be on the thylakoid membrane has not been identified. Three paralogous genes (BST1, BST2, and BST3) belonging to the bestrophin family have been found to be up-regulated in low CO2 conditions, and their expression is controlled by CIA5, a transcription factor that controls many CCM genes. YFP fusions demonstrate that all 3 proteins are located on the thylakoid membrane, and interactome studies indicate that they might associate with chloroplast CCM components. A single mutant defective in BST3 has near-normal growth on low CO2, indicating that the 3 bestrophin-like proteins may have redundant functions. Therefore, an RNA interference (RNAi) approach was adopted to reduce the expression of all 3 genes at once. RNAi mutants with reduced expression of BST1-3 were unable to grow at low CO2 concentrations, exhibited a reduced affinity to inorganic carbon (Ci) compared with the wild-type cells, and showed reduced Ci uptake. We propose that these bestrophin-like proteins are essential components of the CCM that deliver HCO3- accumulated in the chloroplast stroma to CAH3 inside the thylakoid lumen.
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Affiliation(s)
- Ananya Mukherjee
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803
| | - Chun Sing Lau
- Department of Biology, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Charlotte E Walker
- Department of Biology, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Ashwani K Rai
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803
| | - Camille I Prejean
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803
| | - Gary Yates
- Department of Biology, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Thomas Emrich-Mills
- Department of Biology, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Spencer G Lemoine
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803
| | - David J Vinyard
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803
| | - Luke C M Mackinder
- Department of Biology, University of York, Heslington, York YO10 5DD, United Kingdom
| | - James V Moroney
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803;
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Thylakoid localized bestrophin-like proteins are essential for the CO 2 concentrating mechanism of Chlamydomonas reinhardtii. Proc Natl Acad Sci U S A 2019; 116:16915-16920. [PMID: 31391312 PMCID: PMC6708349 DOI: 10.1073/pnas.1909706116] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Models of the CO2 concentrating mechanism (CCM) of green algae and diatoms postulate that chloroplast CO2 is generated from HCO3− brought into the acidic thylakoid lumen and converted to CO2 by specific thylakoid carbonic anhydrases. However, the identity of the transporter required for thylakoid HCO3− uptake has remained elusive. In this work, 3 bestrophin-like proteins, BST1–3, located on the thylakoid membrane have been found to be essential to the CCM of Chlamydomonas. Reduction in expression of BST1–3 markedly reduced the inorganic carbon affinity of the alga. These proteins are prime candidates to be thylakoid HCO3− transporters, a critical currently missing step of the CCM required for future engineering efforts of the Chlamydomonas CCM into plants to improve photosynthesis. The green alga Chlamydomonas reinhardtii possesses a CO2 concentrating mechanism (CCM) that helps in successful acclimation to low CO2 conditions. Current models of the CCM postulate that a series of ion transporters bring HCO3− from outside the cell to the thylakoid lumen, where the carbonic anhydrase 3 (CAH3) dehydrates accumulated HCO3− to CO2, raising the CO2 concentration for Ribulose bisphosphate carboxylase/oxygenase (Rubisco). Previously, HCO3− transporters have been identified at both the plasma membrane and the chloroplast envelope, but the transporter thought to be on the thylakoid membrane has not been identified. Three paralogous genes (BST1, BST2, and BST3) belonging to the bestrophin family have been found to be up-regulated in low CO2 conditions, and their expression is controlled by CIA5, a transcription factor that controls many CCM genes. YFP fusions demonstrate that all 3 proteins are located on the thylakoid membrane, and interactome studies indicate that they might associate with chloroplast CCM components. A single mutant defective in BST3 has near-normal growth on low CO2, indicating that the 3 bestrophin-like proteins may have redundant functions. Therefore, an RNA interference (RNAi) approach was adopted to reduce the expression of all 3 genes at once. RNAi mutants with reduced expression of BST1–3 were unable to grow at low CO2 concentrations, exhibited a reduced affinity to inorganic carbon (Ci) compared with the wild-type cells, and showed reduced Ci uptake. We propose that these bestrophin-like proteins are essential components of the CCM that deliver HCO3− accumulated in the chloroplast stroma to CAH3 inside the thylakoid lumen.
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Terentyev VV, Shukshina AK, Shitov AV. Carbonic anhydrase CAH3 supports the activity of photosystem II under increased pH. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:582-590. [DOI: 10.1016/j.bbabio.2019.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 06/05/2019] [Accepted: 06/15/2019] [Indexed: 11/24/2022]
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Wunder T, Oh ZG, Mueller‐Cajar O. CO
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‐fixing liquid droplets: Towards a dissection of the microalgal pyrenoid. Traffic 2019; 20:380-389. [DOI: 10.1111/tra.12650] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 04/15/2019] [Accepted: 04/16/2019] [Indexed: 12/21/2022]
Affiliation(s)
- Tobias Wunder
- School of Biological SciencesNanyang Technological University Singapore
| | - Zhen Guo Oh
- School of Biological SciencesNanyang Technological University Singapore
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Yamaoka Y, Shin S, Choi BY, Kim H, Jang S, Kajikawa M, Yamano T, Kong F, Légeret B, Fukuzawa H, Li-Beisson Y, Lee Y. The bZIP1 Transcription Factor Regulates Lipid Remodeling and Contributes to ER Stress Management in Chlamydomonas reinhardtii. THE PLANT CELL 2019; 31:1127-1140. [PMID: 30894460 PMCID: PMC6533020 DOI: 10.1105/tpc.18.00723] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 01/29/2019] [Accepted: 03/18/2019] [Indexed: 05/24/2023]
Abstract
Endoplasmic reticulum (ER) stress is caused by the stress-induced accumulation of unfolded proteins in the ER. Here, we identified proteins and lipids that function downstream of the ER stress sensor INOSITOL-REQUIRING ENZYME1 (CrIRE1) that contributes to ER stress tolerance in Chlamydomonas (Chlamydomonas reinhardtii). Treatment with the ER stress inducer tunicamycin resulted in the splicing of a 32-nucleotide fragment of a basic leucine zipper 1 (bZIP1) transcription factor (CrbZIP1) mRNA by CrIRE1 that, in turn, resulted in the loss of the transmembrane domain in CrbZIP1, and the translocation of CrbZIP1 from the ER to the nucleus. Mutants deficient in CrbZIP1 failed to induce the expression of the unfolded protein response genes and grew poorly under ER stress. Levels of diacylglyceryltrimethylhomoserine (DGTS) and pinolenic acid (18:3Δ5,9,12) increased in the parental strains but decreased in the crbzip1 mutants under ER stress. A yeast one-hybrid assay revealed that CrbZIP1 activated the expression of enzymes catalyzing the biosynthesis of DGTS and pinolenic acid. Moreover, two lines harboring independent mutant alleles of Chlamydomonas desaturase (CrDES) failed to synthesize pinolenic acid and were more sensitive to ER stress than were their parental lines. Together, these results indicate that CrbZIP1 is a critical component of the ER stress response mediated by CrIRE1 in Chlamydomonas that acts via lipid remodeling.
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Affiliation(s)
- Yasuyo Yamaoka
- Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Seungjun Shin
- Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Bae Young Choi
- Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Hanul Kim
- Department of Life Science, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Sunghoon Jang
- Department of Life Science, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Masataka Kajikawa
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Takashi Yamano
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Fantao Kong
- Aix Marseille Université, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Biosciences and Biotechnologies Institute of Aix-Marseille, 13108 Saint Paul-Lez-Durance, France
| | - Bertrand Légeret
- Aix Marseille Université, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Biosciences and Biotechnologies Institute of Aix-Marseille, 13108 Saint Paul-Lez-Durance, France
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Yonghua Li-Beisson
- Aix Marseille Université, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Biosciences and Biotechnologies Institute of Aix-Marseille, 13108 Saint Paul-Lez-Durance, France
| | - Youngsook Lee
- Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea
- Department of Life Science, Pohang University of Science and Technology, Pohang 37673, Korea
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Inner lumen proteins stabilize doublet microtubules in cilia and flagella. Nat Commun 2019; 10:1143. [PMID: 30850601 PMCID: PMC6408466 DOI: 10.1038/s41467-019-09051-x] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 02/10/2019] [Indexed: 12/25/2022] Open
Abstract
Motile cilia are microtubule-based organelles that play important roles in most eukaryotes. Although axonemal microtubules are sufficiently stable to withstand their beating motion, it remains unknown how they are stabilized while serving as tracks for axonemal dyneins. To address this question, we have identified two uncharacterized proteins, FAP45 and FAP52, as microtubule inner proteins (MIPs) in Chlamydomonas. These proteins are conserved among eukaryotes with motile cilia. Using cryo-electron tomography (cryo-ET) and high-speed atomic force microscopy (HS-AFM), we show that lack of these proteins leads to a loss of inner protrusions in B-tubules and less stable microtubules. These protrusions are located near the inner junctions of doublet microtubules and lack of both FAP52 and a known inner junction protein FAP20 results in detachment of the B-tubule from the A-tubule, as well as flagellar shortening. These results demonstrate that FAP45 and FAP52 bind to the inside of microtubules and stabilize ciliary axonemes.
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