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Huang Y, Xia P. Biomolecular condensates in plant cells: mediating and integrating environmental signals and development. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 347:112178. [PMID: 38971467 DOI: 10.1016/j.plantsci.2024.112178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 06/23/2024] [Accepted: 06/30/2024] [Indexed: 07/08/2024]
Abstract
In response to the spatiotemporal coordination of various biochemical reactions and membrane-encapsulated organelles, plants appear to provide another effective mechanism for cellular organization by phase separation that allows the internal compartmentalization of cells to form a variety of membrane-less organelles. Most of the research on phase separation has centralized in various non-plant systems, such as yeast and animal systems. Recent studies have shown a remarkable correlation between the formation of condensates in plant systems and the formation of condensates in these systems. Moreover, the last decade has made new advances in phase separation research in the context of plant biology. Here, we provide an overview of the physicochemical forces and molecular factors that drive liquid-liquid phase separation in plant cells and the biochemical characterization of condensates. We then explore new developments in phase separation research specific to plants, discussing examples of condensates found in green plants and detailing their role in plant growth and development. We propose that phase separation may be a conserved organizational mechanism in plant evolution to help plants respond rapidly and effectively to various environmental stresses as sessile organisms.
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Affiliation(s)
- Yang Huang
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Pengguo Xia
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China.
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2
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Nigishi M, Shimakawa G, Yamagishi K, Amano R, Ito S, Tsuji Y, Nagasato C, Matsuda Y. Low-CO2-inducible bestrophins outside the pyrenoid sustain high photosynthetic efficacy in diatoms. PLANT PHYSIOLOGY 2024; 195:1432-1445. [PMID: 38478576 PMCID: PMC11142338 DOI: 10.1093/plphys/kiae137] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 01/18/2024] [Indexed: 06/02/2024]
Abstract
Anion transporters sustain a variety of physiological states in cells. Bestrophins (BSTs) belong to a Cl- and/or HCO3- transporter family conserved in bacteria, animals, algae, and plants. Recently, putative BSTs were found in the green alga Chlamydomonas reinhardtii, where they are upregulated under low CO2 (LC) conditions and play an essential role in the CO2-concentrating mechanism (CCM). The putative BST orthologs are also conserved in diatoms, secondary endosymbiotic algae harboring red-type plastids, but their physiological functions are unknown. Here, we characterized the subcellular localization and expression profile of BSTs in the marine diatoms Phaeodactylum tricornutum (PtBST1 to 4) and Thalassiosira pseudonana (TpBST1 and 2). PtBST1, PtBST2, and PtBST4 were localized at the stroma thylakoid membrane outside of the pyrenoid, and PtBST3 was localized in the pyrenoid. Contrarily, TpBST1 and TpBST2 were both localized in the pyrenoid. These BST proteins accumulated in cells grown in LC but not in 1% CO2 (high CO2 [HC]). To assess the physiological functions, we generated knockout mutants for the PtBST1 gene by genome editing. The lack of PtBST1 decreased photosynthetic affinity for dissolved inorganic carbon to the level comparable with the HC-grown wild type. Furthermore, non-photochemical quenching in LC-grown cells was 1.5 to 2.0 times higher in the mutants than in the wild type. These data suggest that HCO3- transport at the stroma thylakoid membranes by PtBST1 is a critical part of the CO2-evolving machinery of the pyrenoid in the fully induced CCM and that PtBST1 may modulate photoprotection under CO2-limited environments in P. tricornutum.
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Affiliation(s)
- Minori Nigishi
- Department of Bioscience, School of Biological and Environmental Sciences, Kwansei Gakuin University, Sanda, Hyogo 669-1330, Japan
| | - Ginga Shimakawa
- Department of Bioscience, School of Biological and Environmental Sciences, Kwansei Gakuin University, Sanda, Hyogo 669-1330, Japan
| | - Kansei Yamagishi
- Department of Bioscience, School of Biological and Environmental Sciences, Kwansei Gakuin University, Sanda, Hyogo 669-1330, Japan
| | - Ryosuke Amano
- Department of Bioscience, School of Biological and Environmental Sciences, Kwansei Gakuin University, Sanda, Hyogo 669-1330, Japan
| | - Shun Ito
- Department of Bioscience, School of Biological and Environmental Sciences, Kwansei Gakuin University, Sanda, Hyogo 669-1330, Japan
| | - Yoshinori Tsuji
- Department of Bioscience, School of Biological and Environmental Sciences, Kwansei Gakuin University, Sanda, Hyogo 669-1330, Japan
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Chikako Nagasato
- Field Science Center for Northern Biosphere, Muroran Marine Station, Hokkaido University, Muroran 051-0013, Japan
| | - Yusuke Matsuda
- Department of Bioscience, School of Biological and Environmental Sciences, Kwansei Gakuin University, Sanda, Hyogo 669-1330, Japan
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Long BM, Matsuda Y, Moroney JV. Algal chloroplast pyrenoids: Evidence for convergent evolution. Proc Natl Acad Sci U S A 2024; 121:e2402546121. [PMID: 38513078 PMCID: PMC10998615 DOI: 10.1073/pnas.2402546121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024] Open
Affiliation(s)
- Benedict Michael Long
- Discipline of Biological Sciences, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Yusuke Matsuda
- Department of Bioscience, School of Biological and Environmental Sciences, Kansei Gakuin University, Sanda, Hyogo669-1330, Japan
| | - James V. Moroney
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA70803
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Moromizato R, Fukuda K, Suzuki S, Motomura T, Nagasato C, Hirakawa Y. Pyrenoid proteomics reveals independent evolution of the CO 2-concentrating organelle in chlorarachniophytes. Proc Natl Acad Sci U S A 2024; 121:e2318542121. [PMID: 38408230 PMCID: PMC10927497 DOI: 10.1073/pnas.2318542121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 01/25/2024] [Indexed: 02/28/2024] Open
Abstract
Pyrenoids are microcompartments that are universally found in the photosynthetic plastids of various eukaryotic algae. They contain ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and play a pivotal role in facilitating CO2 assimilation via CO2-concentrating mechanisms (CCMs). Recent investigations involving model algae have revealed that pyrenoid-associated proteins participate in pyrenoid biogenesis and CCMs. However, these organisms represent only a small part of algal lineages, which limits our comprehensive understanding of the diversity and evolution of pyrenoid-based CCMs. Here we report a pyrenoid proteome of the chlorarachniophyte alga Amorphochlora amoebiformis, which possesses complex plastids acquired through secondary endosymbiosis with green algae. Proteomic analysis using mass spectrometry resulted in the identification of 154 potential pyrenoid components. Subsequent localization experiments demonstrated the specific targeting of eight proteins to pyrenoids. These included a putative Rubisco-binding linker, carbonic anhydrase, membrane transporter, and uncharacterized GTPase proteins. Notably, most of these proteins were unique to this algal lineage. We suggest a plausible scenario in which pyrenoids in chlorarachniophytes have evolved independently, as their components are not inherited from green algal pyrenoids.
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Affiliation(s)
- Rena Moromizato
- Degree Programs in Life and Earth Sciences, University of Tsukuba, Tsukuba305-8572, Japan
| | - Kodai Fukuda
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba305-8572, Japan
| | - Shigekatsu Suzuki
- Biodiversity Division, National Institute for Environmental Studies, Tsukuba305-8506, Japan
| | - Taizo Motomura
- Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran051-0013, Japan
| | - Chikako Nagasato
- Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran051-0013, Japan
| | - Yoshihisa Hirakawa
- Institute of Life and Environmental Sciences, University of Tsukuba, Tsukuba305-8572, Japan
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Atkinson N, Stringer R, Mitchell SR, Seung D, McCormick AJ. SAGA1 and SAGA2 promote starch formation around proto-pyrenoids in Arabidopsis chloroplasts. Proc Natl Acad Sci U S A 2024; 121:e2311013121. [PMID: 38241434 PMCID: PMC10823261 DOI: 10.1073/pnas.2311013121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 12/11/2023] [Indexed: 01/21/2024] Open
Abstract
The pyrenoid is a chloroplastic microcompartment in which most algae and some terrestrial plants condense the primary carboxylase, Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase) as part of a CO2-concentrating mechanism that improves the efficiency of CO2 capture. Engineering a pyrenoid-based CO2-concentrating mechanism (pCCM) into C3 crop plants is a promising strategy to enhance yield capacities and resilience to the changing climate. Many pyrenoids are characterized by a sheath of starch plates that is proposed to act as a barrier to limit CO2 diffusion. Recently, we have reconstituted a phase-separated "proto-pyrenoid" Rubisco matrix in the model C3 plant Arabidopsis thaliana using proteins from the alga with the most well-studied pyrenoid, Chlamydomonas reinhardtii [N. Atkinson, Y. Mao, K. X. Chan, A. J. McCormick, Nat. Commun. 11, 6303 (2020)]. Here, we describe the impact of introducing the Chlamydomonas proteins StArch Granules Abnormal 1 (SAGA1) and SAGA2, which are associated with the regulation of pyrenoid starch biogenesis and morphology. We show that SAGA1 localizes to the proto-pyrenoid in engineered Arabidopsis plants, which results in the formation of atypical spherical starch granules enclosed within the proto-pyrenoid condensate and adjacent plate-like granules that partially cover the condensate, but without modifying the total amount of chloroplastic starch accrued. Additional expression of SAGA2 further increases the proportion of starch synthesized as adjacent plate-like granules that fully encircle the proto-pyrenoid. Our findings pave the way to assembling a diffusion barrier as part of a functional pCCM in vascular plants, while also advancing our understanding of the roles of SAGA1 and SAGA2 in starch sheath formation and broadening the avenues for engineering starch morphology.
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Affiliation(s)
- Nicky Atkinson
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, EdinburghEH9 3BF, United Kingdom
- Centre of Engineering Biology, University of Edinburgh, EdinburghEH9 3BF, United Kingdom
| | - Rhea Stringer
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, NorwichNR4 7UH, United Kingdom
| | - Stephen R. Mitchell
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, EdinburghEH9 3BF, United Kingdom
| | - David Seung
- Department of Biochemistry and Metabolism, John Innes Centre, Norwich Research Park, NorwichNR4 7UH, United Kingdom
| | - Alistair J. McCormick
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, EdinburghEH9 3BF, United Kingdom
- Centre of Engineering Biology, University of Edinburgh, EdinburghEH9 3BF, United Kingdom
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Shimakawa G, Matsuda Y. Extra O 2 evolution reveals an O 2-independent alternative electron sink in photosynthesis of marine diatoms. PHOTOSYNTHESIS RESEARCH 2024; 159:61-68. [PMID: 38316719 DOI: 10.1007/s11120-023-01073-3] [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: 08/31/2023] [Accepted: 12/27/2023] [Indexed: 02/07/2024]
Abstract
Following the principle of oxygenic photosynthesis, electron transport in the thylakoid membranes (i.e., light reaction) generates ATP and NADPH from light energy, which is subsequently utilized for CO2 fixation in the Calvin-Benson-Bassham cycle (i.e., dark reaction). However, light and dark reactions could discord when an alternative electron flow occurs with a rate comparable to the linear electron flow. Here, we quantitatively monitored O2 and total dissolved inorganic carbon (DIC) during photosynthesis in the pennate diatom Phaeodactylum tricornutum, and found that evolved O2 was larger than the consumption of DIC, which was consistent with 14CO2 measurements in literature. In our measurements, the stoichiometry of O2 evolution to DIC consumption was always around 1.5 during photosynthesis at different DIC concentrations. The same stoichiometry was observed in the cells grown under different CO2 concentrations and nitrogen sources except for the nitrogen-starved cells showing O2 evolution 2.5 times larger than DIC consumption. An inhibitor to nitrogen assimilation did not affect the extra O2 evolution. Further, the same physiological phenomenon was observed in the centric diatom Thalassiosira pseudonana. Based on the present dataset, we propose that the marine diatoms possess the metabolic pathway(s) functioning as the O2-independent electron sink under steady state photosynthesis that reaches nearly half of electron flux of the Calvin-Benson-Bassham cycle.
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Affiliation(s)
- Ginga Shimakawa
- Department of Bioscience, School of Biological and Environmental Sciences, Kwansei Gakuin University, 1 Gakuen Uegahara, Sanda, Hyogo, 669-1330, Japan.
| | - Yusuke Matsuda
- Department of Bioscience, School of Biological and Environmental Sciences, Kwansei Gakuin University, 1 Gakuen Uegahara, Sanda, Hyogo, 669-1330, Japan
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Gutierrez-Beltran E, Strader L, Bozhkov PV. Focus on biomolecular condensates. THE PLANT CELL 2023; 35:3155-3157. [PMID: 37352160 PMCID: PMC10473217 DOI: 10.1093/plcell/koad182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 06/21/2023] [Accepted: 06/21/2023] [Indexed: 06/25/2023]
Affiliation(s)
- Emilio Gutierrez-Beltran
- Instituto de Bioquimica Vegetal y Fotosintesis, Consejo Superior de Investigaciones Cientificas (CSIC)-Universidad de Sevilla, Sevilla 41092, Spain
- Departamento de Bioquimica Vegetal y Biologia Molecular, Facultad de Biologia, Universidad de Sevilla, Sevilla 41012, Spain
- Guest Editor, The Plant Cell, American Society of Plant Biologists, USA
| | - Lucia Strader
- Department of Biology, Duke University, Durham, NC 27708, USA
- Senior Editor, The Plant Cell, American Society of Plant Biologists, USA
| | - Peter V Bozhkov
- Guest Editor, The Plant Cell, American Society of Plant Biologists, USA
- Department of Molecular Sciences, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala 75007, Sweden
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