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Gee CW, Andersen-Ranberg J, Boynton E, Rosen RZ, Jorgens D, Grob P, Holman HYN, Niyogi KK. Implicating the red body of Nannochloropsis in forming the recalcitrant cell wall polymer algaenan. Nat Commun 2024; 15:5456. [PMID: 38937455 PMCID: PMC11211512 DOI: 10.1038/s41467-024-49277-y] [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: 10/05/2023] [Accepted: 05/31/2024] [Indexed: 06/29/2024] Open
Abstract
Stramenopile algae contribute significantly to global primary productivity, and one class, Eustigmatophyceae, is increasingly studied for applications in high-value lipid production. Yet much about their basic biology remains unknown, including the nature of an enigmatic, pigmented globule found in vegetative cells. Here, we present an in-depth examination of this "red body," focusing on Nannochloropsis oceanica. During the cell cycle, the red body forms adjacent to the plastid, but unexpectedly it is secreted and released with the autosporangial wall following cell division. Shed red bodies contain antioxidant ketocarotenoids, and overexpression of a beta-carotene ketolase results in enlarged red bodies. Infrared spectroscopy indicates long-chain, aliphatic lipids in shed red bodies and cell walls, and UHPLC-HRMS detects a C32 alkyl diol, a potential precursor of algaenan, a recalcitrant cell wall polymer. We propose that the red body transports algaenan precursors from plastid to apoplast to be incorporated into daughter cell walls.
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Affiliation(s)
- Christopher W Gee
- Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Johan Andersen-Ranberg
- University of Copenhagen, Department of Plant and Environmental Sciences, Frederiksberg, DK-1871, Denmark
| | - Ethan Boynton
- Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Rachel Z Rosen
- Department of Chemistry, University of California, Berkeley, CA, 94702, USA
| | - Danielle Jorgens
- Electron Microscope Laboratory, University of California, Berkeley, CA, 94720, USA
| | - Patricia Grob
- Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720, USA
- California Institute of Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA
| | - Hoi-Ying N Holman
- Electron Microscope Laboratory, University of California, Berkeley, CA, 94720, USA
| | - Krishna K Niyogi
- Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720, USA.
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA.
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
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Alp-Turgut FN, Ozfidan-Konakci C, Arikan B, Comak G, Yildiztugay E. Graphene oxide-based aerogel stimulates growth, mercury accumulation, photosynthesis-related gene expression, antioxidant efficiency and redox status in wheat under mercury exposure. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 342:123117. [PMID: 38086507 DOI: 10.1016/j.envpol.2023.123117] [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: 09/19/2023] [Revised: 12/05/2023] [Accepted: 12/06/2023] [Indexed: 12/17/2023]
Abstract
Mercury (Hg) pollution is a global concern in cropland systems. Hg contamination causes a disruption in the growth, energy metabolism, redox balance, and photosynthetic activity of plants. In the removal of Hg toxicity, a recent critical strategy is the use of aerogels with biodegradability and biocompatibility. However, it is unknown how graphene oxide-based aerogels stimulate the defense systems in wheat plants exposed to Hg toxicity. Therefore, in this study, the photosynthetic, genetic, and biochemical effects of reduced graphene oxide aerogel treatments (gA; 50-100-250 mg L-1) were examined in wheat (Triticum aestivum) under Hg stress (50 μM HgCl2). The relative growth rate (RGR) significantly decreased (84%) in response to Hg stress. However, the reduced RGR and water relations (RWC) of wheat were improved by gA treatments. The impaired gas exchange levels (stomatal conductance, carbon assimilation rate, intercellular CO2 concentrations, and transpiration rate) caused by stress were reversed under Hg plus gAs. Additionally, stress hampered chlorophyll fluorescence (Fv/Fo, Fv/Fm), and under Hg toxicity the expression of psaA genes was reduced (>0.4-fold), but psaB gene was significantly up-regulated (>3-fold) which are the genes involved in PSI. By increasing expression patterns of both genes relating to PSI, gAs reversed the adverse consequences on Fv/Fo and Fv/Fm in the presence of excessive Hg concentration. The activities of glutathione S-transferase (GST), glutathione reductase (GR), catalase (CAT), ascorbate peroxidase (APX) and dehydroascorbate reductase (DHAR) decreased under Hg toxicity. On the other hand, the activities of superoxide dismutase (SOD), APX, GST, and glutathione peroxidase (GPX) increased following gA treatments against stress, leading to the successful elimination of toxic levels of H2O2 and lipid peroxidation (TBARS content) by decreasing the levels by about 30%, and 40%, respectively. By modulating enzyme/non-enzyme activity/contents including the AsA-GSH cycle, gAs contributed to the protection of the cellular redox state. Most important of all, gA applications were able to reduce Hg intake by approximately 66%. Therefore, these results showed that gAs were effective in highly inhibiting Hg uptake and could significantly increase wheat tolerance to toxicity by eliminating Hg-induced oxidative damage and inhibiting metabolic processes involved in photosynthesis. The findings obtained from the study provide a new perspective on the alleviation roles of reduced graphene oxide aerogels as an effective adsorbent for decreasing damages of mercury toxicity in wheat plants.
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Affiliation(s)
- Fatma Nur Alp-Turgut
- Department of Biotechnology, Faculty of Science, Selcuk University, Selcuklu, 42130, Konya, Turkey.
| | - Ceyda Ozfidan-Konakci
- Department of Molecular Biology and Genetics, Faculty of Science, Necmettin Erbakan University, Meram, 42090, Konya, Turkey.
| | - Busra Arikan
- Department of Biotechnology, Faculty of Science, Selcuk University, Selcuklu, 42130, Konya, Turkey.
| | - Gurbuz Comak
- Department of Chemical Engineering, Faculty of Engineering, Mersin University, Mersin, 33100, Turkey.
| | - Evren Yildiztugay
- Department of Biotechnology, Faculty of Science, Selcuk University, Selcuklu, 42130, Konya, Turkey.
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Agarwal A, Selvam A, Majood M, Agrawal O, Chakrabarti S, Mukherjee M. Carbon nanosheets to unravel the production of bioactive compounds from microalgae: A robust approach in drug discovery. Drug Discov Today 2023; 28:103586. [PMID: 37080385 DOI: 10.1016/j.drudis.2023.103586] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 04/10/2023] [Accepted: 04/11/2023] [Indexed: 04/22/2023]
Abstract
The conglomeration of active pharmaceutical ingredients (APIs) has influenced the development of life-saving drugs. These APIs are customarily synthetic products, albeit with adverse side effects. Thus, to overcome the bottlenecks associated with synthetically derived APIs, the approach of photocatalytically obtaining bioactive compounds from natural ingredients has emerged. Amid the pool of photoactive nanomaterials, this short review emphasizes the intelligent strategy of exploiting photoactive carbon nanosheets to photocatalytically derive bioactive compounds from natural algal biomass to treat many acute or chronic medical conditions. Carbon nanosheets result in phototrophic harvesting of bioactive compounds from microalgae as a result of their being an effective biocatalyst that increases the rate of photosynthesis. To understand the clinical translation of bioactive compounds, the pharmacodynamics of algal bioactive compounds are highlighted to determine the practicality and feasibility of using this green approach for pharmaceutical drug discovery.
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Affiliation(s)
- Aakanksha Agarwal
- Amity Institute of Click Chemistry Research and Studies, Amity University Uttar Pradesh, Noida, 201313, India
| | - Abhyavartin Selvam
- Amity Institute of Click Chemistry Research and Studies, Amity University Uttar Pradesh, Noida, 201313, India; Amity Institute of Nanotechnology, Amity University Uttar Pradesh, Noida, 201313, India
| | - Misba Majood
- Amity Institute of Click Chemistry Research and Studies, Amity University Uttar Pradesh, Noida, 201313, India
| | - Omnarayan Agrawal
- Amity Institute of Click Chemistry Research and Studies, Amity University Uttar Pradesh, Noida, 201313, India
| | - Sandip Chakrabarti
- Amity Institute of Nanotechnology, Amity University Uttar Pradesh, Noida, 201313, India
| | - Monalisa Mukherjee
- Amity Institute of Click Chemistry Research and Studies, Amity University Uttar Pradesh, Noida, 201313, India.
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Wu J, Hu J, Wang L, Zhao L, Ma F. Responses of Phragmites australis to copper stress: A combined analysis of plant morphology, physiology and proteomics. PLANT BIOLOGY (STUTTGART, GERMANY) 2021; 23:351-362. [PMID: 32810882 DOI: 10.1111/plb.13175] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 08/03/2020] [Indexed: 05/11/2023]
Abstract
Few relevant research attempts have been made to determine heavy metal resistance mechanisms of rhizomatous perennial plants. Thus, it is pertinent to investigate the physiological and biochemical changes in Phragmites australis under metal-stressed conditions to facilitate the development of strategies to enhance copper (Cu) tolerance. We measured parameters related to plant growth and development, metal translocation and physiological responses of P. australis subjected to Cu stress. In addition, the differentially expressed proteins (DEP) were evaluated using the isobaric tag for relative and absolute quantification (iTRAQ) system. A large amount of copper accumulates in the roots of P.australis, but the growth parameters were not sensitive to Cu. However, the high concentration of Cu reduced the content of chlorophyll a and chlorophyll b, and the expression of important photosynthesis proteins PsbD, PsbO and PsaA were all down-regulated, so photosynthesis was inhibited. In contrast, the content of ascorbic acid and proline both increased with the increase of copper stress. P.australis fixed a large amount of Cu in its roots, limiting the migration of Cu to other parts of the plant. Moreover, Cu stress can affect photosynthesis by inhibiting the activity of PSI, PSII and LHCII. In addition, P.australis synthesizes ascorbic acid through the D-mannose/L-galactose pathway, and synthesizes proline through the ornithine pathway. Ascorbic acid and proline can increase Cu tolerance and protect photosynthesis. These results provide a theoretical basis for understanding the tolerance and repair mechanisms of plants in response to heavy metal pollution.
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Affiliation(s)
- J Wu
- School of Environmental Science, Liaoning University, Shenyang, China
| | - J Hu
- School of Environmental Science, Liaoning University, Shenyang, China
| | - L Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, China
| | - L Zhao
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, China
| | - F Ma
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, China
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Litvín R, Bína D, Herbstová M, Pazderník M, Kotabová E, Gardian Z, Trtílek M, Prášil O, Vácha F. Red-shifted light-harvesting system of freshwater eukaryotic alga Trachydiscus minutus (Eustigmatophyta, Stramenopila). PHOTOSYNTHESIS RESEARCH 2019; 142:137-151. [PMID: 31375979 DOI: 10.1007/s11120-019-00662-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 07/22/2019] [Indexed: 06/10/2023]
Abstract
Survival of phototrophic organisms depends on their ability to collect and convert enough light energy to support their metabolism. Phototrophs can extend their absorption cross section by using diverse pigments and by tuning the properties of these pigments via pigment-pigment and pigment-protein interaction. It is well known that some cyanobacteria can grow in heavily shaded habitats by utilizing far-red light harvested with far-red-absorbing chlorophylls d and f. We describe a red-shifted light-harvesting system based on chlorophyll a from a freshwater eustigmatophyte alga Trachydiscus minutus (Eustigmatophyceae, Goniochloridales). A comprehensive characterization of the photosynthetic apparatus of T. minutus is presented. We show that thylakoid membranes of T. minutus contain light-harvesting complexes of several sizes differing in the relative amount of far-red chlorophyll a forms absorbing around 700 nm. The pigment arrangement of the major red-shifted light-harvesting complex is similar to that of the red-shifted antenna of a marine alveolate alga Chromera velia. Evolutionary aspects of the algal far-red light-harvesting complexes are discussed. The presence of these antennas in eustigmatophyte algae opens up new ways to modify organisms of this promising group for effective use of far-red light in mass cultures.
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Affiliation(s)
- Radek Litvín
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
- Biology Centre, The Czech Academy of Sciences, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - David Bína
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic.
- Biology Centre, The Czech Academy of Sciences, Branišovská 31, 370 05, České Budějovice, Czech Republic.
| | - Miroslava Herbstová
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
- Biology Centre, The Czech Academy of Sciences, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Marek Pazderník
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
- Institute of Microbiology, The Czech Academy of Sciences, Opatovický mlýn, 379 81, Třeboň, Czech Republic
| | - Eva Kotabová
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
- Institute of Microbiology, The Czech Academy of Sciences, Opatovický mlýn, 379 81, Třeboň, Czech Republic
| | - Zdenko Gardian
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
- Biology Centre, The Czech Academy of Sciences, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Martin Trtílek
- PSI (Photon Systems Instruments), spol. s r.o. Drásov 470, 664 24, Drásov, Czech Republic
| | - Ondřej Prášil
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
- Institute of Microbiology, The Czech Academy of Sciences, Opatovický mlýn, 379 81, Třeboň, Czech Republic
| | - František Vácha
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic
- Biology Centre, The Czech Academy of Sciences, Branišovská 31, 370 05, České Budějovice, Czech Republic
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Büchel C. Light harvesting complexes in chlorophyll c-containing algae. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1861:148027. [PMID: 31153887 DOI: 10.1016/j.bbabio.2019.05.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/22/2019] [Accepted: 05/24/2019] [Indexed: 12/30/2022]
Abstract
Besides the so-called 'green lineage' of eukaryotic photosynthetic organisms that include vascular plants, a huge variety of different algal groups exist that also harvest light by means of membrane intrinsic light harvesting proteins (Lhc). The main taxa of these algae are the Cryptophytes, Haptophytes, Dinophytes, Chromeridae and the Heterokonts, the latter including diatoms, brown algae, Xanthophyceae and Eustigmatophyceae amongst others. Despite the similarity in Lhc proteins between vascular plants and these algae, pigmentation is significantly different since no Chl b is bound, but often replaced by Chl c, and a large diversity in carotenoids functioning in light harvesting and/or photoprotection is present. Due to the presence of Chl c in most of the taxa the name 'Chl c-containing organisms' has become common, however, Chl b-less is more precise since some harbour Lhc proteins that only bind one type of Chl, Chl a. In recent years huge progress has been made about the occurrence and function of Lhc in diatoms, so-called fucoxanthin chlorophyll proteins (FCP), where also the first molecular structure became available recently. In addition, especially energy transfer amongst the unusual pigments bound was intensively studied in many of these groups. This review summarises the present knowledge about the molecular structure, the arrangement of the different Lhc in complexes, the excitation energy transfer abilities and the involvement in photoprotection of the different Lhc systems in the so-called Chl c-containing organisms. This article is part of a Special Issue entitled Light harvesting, edited by Dr. Roberta Croce.
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Affiliation(s)
- Claudia Büchel
- Institute of Molecular Biosciences, Goethe University Frankfurt, Max-von-Laue Straße 9, 60438 Frankfurt, Germany.
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Kuthanová Trsková E, Bína D, Santabarbara S, Sobotka R, Kaňa R, Belgio E. Isolation and characterization of CAC antenna proteins and photosystem I supercomplex from the cryptophytic alga Rhodomonas salina. PHYSIOLOGIA PLANTARUM 2019; 166:309-319. [PMID: 30677144 DOI: 10.1111/ppl.12928] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 01/17/2019] [Indexed: 06/09/2023]
Abstract
In the present paper, we report an improved method combining sucrose density gradient with ion-exchange chromatography for the isolation of pure chlorophyll a/c antenna proteins from the model cryptophytic alga Rhodomonas salina. Antennas were used for in vitro quenching experiments in the absence of xanthophylls, showing that protein aggregation is a plausible mechanism behind non-photochemical quenching in R. salina. From sucrose gradient, it was also possible to purify a functional photosystem I supercomplex, which was in turn characterized by steady-state and time-resolved fluorescence spectroscopy. R. salina photosystem I showed a remarkably fast photochemical trapping rate, similar to what recently reported for other red clade algae such as Chromera velia and Phaeodactylum tricornutum. The method reported therefore may also be suitable for other still partially unexplored algae, such as cryptophytes.
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Affiliation(s)
- Eliška Kuthanová Trsková
- Institute of Microbiology, Academy of Sciences of the Czech Republic, 379 81, Třeboň, Czech Republic
- Faculty of Science, University of South Bohemia in České Budějovice, 370 05, České Budějovice, Czech Republic
| | - David Bína
- Faculty of Science, University of South Bohemia in České Budějovice, 370 05, České Budějovice, Czech Republic
- Institute of Plant Molecular Biology, Biology Centre CAS, 370 05, České Budějovice, Czech Republic
| | - Stefano Santabarbara
- Photosynthesis Research Unit, Centro Studi sulla Biologia Cellulare e Molecolare delle Piante, 20133, Milan, Italy
| | - Roman Sobotka
- Institute of Microbiology, Academy of Sciences of the Czech Republic, 379 81, Třeboň, Czech Republic
- Faculty of Science, University of South Bohemia in České Budějovice, 370 05, České Budějovice, Czech Republic
| | - Radek Kaňa
- Institute of Microbiology, Academy of Sciences of the Czech Republic, 379 81, Třeboň, Czech Republic
- Faculty of Science, University of South Bohemia in České Budějovice, 370 05, České Budějovice, Czech Republic
| | - Erica Belgio
- Institute of Microbiology, Academy of Sciences of the Czech Republic, 379 81, Třeboň, Czech Republic
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Energy transfer dynamics in a red-shifted violaxanthin-chlorophyll a light-harvesting complex. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:111-120. [DOI: 10.1016/j.bbabio.2018.11.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Revised: 10/15/2018] [Accepted: 11/07/2018] [Indexed: 11/21/2022]
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Wang F, Huang L, Gao B, Zhang C. Optimum Production Conditions, Purification, Identification, and Antioxidant Activity of Violaxanthin from Microalga Eustigmatos cf. polyphem (Eustigmatophyceae). Mar Drugs 2018; 16:md16060190. [PMID: 29857588 PMCID: PMC6025076 DOI: 10.3390/md16060190] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 05/24/2018] [Accepted: 05/30/2018] [Indexed: 12/26/2022] Open
Abstract
Violaxanthin is a major xanthophyll pigment in the microalga Eustigmatos cf. polyphem, but the amount produced after propagation can vary depending upon culture conditions. In this study, the effects of cultivation time, nitrogen concentration, light intensity, and culture mode on violaxanthin production were investigated. The results showed that this microalga vigorously grew and maintained a high level of violaxanthin in the fed-batch culture, and the highest violaxanthin productivity of 1.10 ± 0.03 mg L−1 d−1 was obtained under low light illumination with 18 mM of initial nitrogen supply for ten days. Additionally, violaxanthin was purified from E. cf. polyphem by silica gel chromatography and preparative high-performance liquid chromatography (PHPLC), and identified with high-resolution mass spectrometry (HRMS). The antioxidant activity of the purified violaxanthin was evaluated by three tests in vitro: reducing power assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2-azobis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical assays. The strongest inhibition of purified violaxanthin occurred during the scavenging of ABTS+ radicals, with EC50 of 15.25 μg mL−1. In conclusion, this is the first report to investigate the effects of different culture conditions on violaxanthin accumulation in E. cf. polyphem and provide a novel source for the production of violaxanthin that can be used for food and pharmaceutical applications.
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Affiliation(s)
- Feifei Wang
- Institute of Hydrobiology, Department of Ecology, Jinan University, Guangzhou 510632, China.
| | - Luodong Huang
- Institute of Hydrobiology, Department of Ecology, Jinan University, Guangzhou 510632, China.
| | - Baoyan Gao
- Institute of Hydrobiology, Department of Ecology, Jinan University, Guangzhou 510632, China.
| | - Chengwu Zhang
- Institute of Hydrobiology, Department of Ecology, Jinan University, Guangzhou 510632, China.
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Umetani I, Kunugi M, Yokono M, Takabayashi A, Tanaka A. Evidence of the supercomplex organization of photosystem II and light-harvesting complexes in Nannochloropsis granulata. PHOTOSYNTHESIS RESEARCH 2018; 136:49-61. [PMID: 28856533 DOI: 10.1007/s11120-017-0438-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 08/27/2017] [Indexed: 06/07/2023]
Abstract
Diverse light-harvesting complexes (LHCs) have been found in photosynthetic microalgae that originated from secondary endosymbiosis involving primary red algae. However, the associations between LHCs and photosystem I (PSI) and photosystem II (PSII) in these microalgae are not fully understood. Eustigmatophyta is a red algal lineage that appears to have a unique organization in its photosynthetic machinery, consisting of only chlorophyll a and carotenoids that are atypical compared with other closely related groups. In this study, the supramolecular organization of pigment-protein complexes in the eustigmatophyte alga, Nannochloropsis granulata was investigated using Clear Native (CN) PAGE coupled with two-dimensional (2D) SDS-PAGE. Our results showed two slowly migrating green bands that corresponded to PSII supercomplexes, which consisted of reaction centers and LHCs. These green bands were also characterized as PSII complexes by their low temperature fluorescence emission spectra. The protein subunits of the PSII-LHC resolved by 2D CN/SDS-PAGE were analyzed by mass spectrometry, and four different LHC proteins were identified. Phylogenetic analysis of the identified LHC protein sequences revealed that they belonged to four different Lhc groups; (1) stress-related Lhcx proteins, (2) fucoxanthin chlorophyll a/c-binding Lhcf proteins, (3) red-shifted Chromera light-harvesting proteins (Red-CLH), and (4) Lhcr proteins, which are commonly found in organisms possessing red algal plastids. This is the first report showing evidence of a pigment-protein supercomplex consisting of PSII and LHCs, and to identify PSII-associated LHC proteins in Nannochloropsis.
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Affiliation(s)
- Ikumi Umetani
- Institute of Low Temperature Science, Hokkaido University, N19 W8 Kita-Ku, Sapporo, 060-0819, Japan
- Department of Natural Sciences and Environmental Health, University College of Southeast Norway, Gullbringvegen 36, 3880, Bø, Norway
| | - Motoshi Kunugi
- Institute of Low Temperature Science, Hokkaido University, N19 W8 Kita-Ku, Sapporo, 060-0819, Japan
| | - Makio Yokono
- Institute of Low Temperature Science, Hokkaido University, N19 W8 Kita-Ku, Sapporo, 060-0819, Japan
| | - Atsushi Takabayashi
- Institute of Low Temperature Science, Hokkaido University, N19 W8 Kita-Ku, Sapporo, 060-0819, Japan.
| | - Ayumi Tanaka
- Institute of Low Temperature Science, Hokkaido University, N19 W8 Kita-Ku, Sapporo, 060-0819, Japan
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Perin G, Simionato D, Bellan A, Carone M, Occhipinti A, Maffei ME, Morosinotto T. Cultivation in industrially relevant conditions has a strong influence on biological properties and performances of Nannochloropsis gaditana genetically modified strains. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.10.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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12
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Extensive gain and loss of photosystem I subunits in chromerid algae, photosynthetic relatives of apicomplexans. Sci Rep 2017; 7:13214. [PMID: 29038514 PMCID: PMC5643376 DOI: 10.1038/s41598-017-13575-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 09/26/2017] [Indexed: 12/16/2022] Open
Abstract
In oxygenic photosynthesis the initial photochemical processes are carried out by photosystem I (PSI) and II (PSII). Although subunit composition varies between cyanobacterial and plastid photosystems, the core structures of PSI and PSII are conserved throughout photosynthetic eukaryotes. So far, the photosynthetic complexes have been characterised in only a small number of organisms. We performed in silico and biochemical studies to explore the organization and evolution of the photosynthetic apparatus in the chromerids Chromera velia and Vitrella brassicaformis, autotrophic relatives of apicomplexans. We catalogued the presence and location of genes coding for conserved subunits of the photosystems as well as cytochrome b6f and ATP synthase in chromerids and other phototrophs and performed a phylogenetic analysis. We then characterised the photosynthetic complexes of Chromera and Vitrella using 2D gels combined with mass-spectrometry and further analysed the purified Chromera PSI. Our data suggest that the photosynthetic apparatus of chromerids underwent unique structural changes. Both photosystems (as well as cytochrome b6f and ATP synthase) lost several canonical subunits, while PSI gained one superoxide dismutase (Vitrella) or two superoxide dismutases and several unknown proteins (Chromera) as new regular subunits. We discuss these results in light of the extraordinarily efficient photosynthetic processes described in Chromera.
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