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[PMID]:29253814
[Au] Autor:Faseela P; Puthur JT
[Ad] Endereço:Plant Physiology and Biochemistry Division, Department of Botany, University of Calicut, Malappuram, Kerala 673635, India.
[Ti] Título:The imprints of the high light and UV-B stresses in Oryza sativa L. 'Kanchana' seedlings are differentially modulated.
[So] Source:J Photochem Photobiol B;178:551-559, 2018 Jan.
[Is] ISSN:1873-2682
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:High light and ultraviolet-B radiation (UV-B) are generally considered to have negative impact on photosynthesis and plant growth. The present study evaluates the tolerance potential of three cultivars of Oryza sativa L. (Kanchana, Mattatriveni and Harsha) seedlings towards high light and UV-B stress on the basis of photosynthetic pigment degradation, chlorophyll a fluorescence parameters and rate of lipid peroxidation, expressed by malondialdehyde content. Surprisingly, it was revealed that Kanchana was the most sensitive cultivar towards high light and at the same time it was the most tolerant cultivar towards UV-B stress. This contrasting feature of Kanchana towards high light and UV-B tolerance was further studied by analyzing photosystem (PS) I and II activity, mitochondrial activity, chlorophyll a fluorescence transient, enzymatic and non-enzymatic antioxidant defense system. Due to the occurrence of more PS I and PSII damages, the inhibition of photochemical efficiency and emission of dissipated energy as heat or fluorescence per PSII reaction center was higher upon high light exposure than UV-B treatments in rice seedlings of Kanchana. The mitochondrial activity was also found to be drastically altered upon high light as compared to UV-B treatments. The UV-B induced accumulation of non-enzymatic antioxidants (proline, total phenolics, sugar and ascorbate) and enzymatic antioxidants (ascorbate peroxidase, guaiacol peroxidase, superoxide dismutase and glutathione reductase) in rice seedlings than those subjected to high light exposure afforded more efficient protection against UV-B radiation in rice seedlings. Our results proved that high tolerance of Kanchana towards UV-B than high light treatments, correlated linearly with the protected photosynthetic and mitochondrial machinery which was provided by upregulation of antioxidants particularly by total phenolics, ascorbate and ascorbate peroxidase in rice seedlings. Data presented in this study conclusively proved that rice cultivar Kanchana respond to different environmental signals independently and tolerance mechanisms to individual stress factors was also varied.
[Mh] Termos MeSH primário: Oryza/efeitos da radiação
Raios Ultravioleta
[Mh] Termos MeSH secundário: Antioxidantes/metabolismo
Ascorbato Peroxidases/metabolismo
Ácido Ascórbico/metabolismo
Clorofila/química
Clorofila/metabolismo
Malondialdeído/metabolismo
Mitocôndrias/metabolismo
Mitocôndrias/efeitos da radiação
Oryza/crescimento & desenvolvimento
Fenóis/metabolismo
Fotossíntese/efeitos da radiação
Complexo de Proteína do Fotossistema I/metabolismo
Complexo de Proteína do Fotossistema II/metabolismo
Prolina/metabolismo
Plântulas/metabolismo
Plântulas/efeitos da radiação
Espectrometria de Fluorescência
Regulação para Cima/efeitos da radiação
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antioxidants); 0 (Phenols); 0 (Photosystem I Protein Complex); 0 (Photosystem II Protein Complex); 1406-65-1 (Chlorophyll); 4Y8F71G49Q (Malondialdehyde); 9DLQ4CIU6V (Proline); EC 1.11.1.11 (Ascorbate Peroxidases); PQ6CK8PD0R (Ascorbic Acid); YF5Q9EJC8Y (chlorophyll a)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180212
[Lr] Data última revisão:
180212
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171219
[St] Status:MEDLINE


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[PMID]:29196904
[Au] Autor:Zienkiewicz M; Krupnik T; Drozak A; Wasilewska W; Golke A; Romanowska E
[Ad] Endereço:Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland. maximus@biol.uw.edu.pl.
[Ti] Título:Deletion of psbQ' gene in Cyanidioschyzon merolae reveals the function of extrinsic PsbQ' in PSII.
[So] Source:Plant Mol Biol;96(1-2):135-149, 2018 Jan.
[Is] ISSN:1573-5028
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:KEY MESSAGE: We have successfully produced single-cell colonies of C. merolae mutants, lacking the PsbQ' subunit in its PSII complex by application of DTA-aided mutant selection. We have investigated the physiological changes in PSII function and structure and proposed a tentative explanation of the function of PsbQ' subunit in the PSII complex. We have improved the selectivity of the Cyanidioschyzon merolae nuclear transformation method by the introduction of diphtheria toxin genes into the transformation vector as an auxiliary selectable marker. The revised method allowed us to obtained single-cell colonies of C. merolae, lacking the gene of the PsbQ' extrinsic protein. The efficiency of gene replacement was extraordinarily high, allowing for a complete deletion of the gene of interest, without undesirable illegitimate integration events. We have confirmed the absence of PsbQ' protein at genetic and protein level. We have characterized the physiology of mutant cells and isolated PSII protein complex and concluded that PsbQ' is involved in nuclear regulation of PSII activity, by influencing several parameters of PSII function. Among these: oxygen evolving activity, partial dissociation of PsbV, regulation of dimerization, downsizing of phycobilisomes rods and regulation of zeaxanthin abundance. The adaptation of cellular physiology appeared to favorite upregulation of PSII and concurrent downregulation of PSI, resulting in an imbalance of energy distribution, decrease of photosynthesis and inhibition of cell proliferation.
[Mh] Termos MeSH primário: Fotossíntese/genética
Complexo de Proteína do Fotossistema II/genética
Complexo de Proteína do Fotossistema II/metabolismo
[Mh] Termos MeSH secundário: Cloranfenicol O-Acetiltransferase/genética
Cloranfenicol O-Acetiltransferase/metabolismo
Rodófitas/genética
Rodófitas/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Photosystem II Protein Complex); EC 2.3.1.28 (Chloramphenicol O-Acetyltransferase)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180212
[Lr] Data última revisão:
180212
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171203
[St] Status:MEDLINE
[do] DOI:10.1007/s11103-017-0685-6


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[PMID]:29211990
[Au] Autor:Daskalakis V; Papadatos S
[Ad] Endereço:Department of Environmental Science and Technology, Cyprus University of Technology, Limassol, Cyprus. Electronic address: evangelos.daskalakis@cut.ac.cy.
[Ti] Título:The Photosystem II Subunit S under Stress.
[So] Source:Biophys J;113(11):2364-2372, 2017 Dec 05.
[Is] ISSN:1542-0086
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Nonphotochemical quenching is the protective mechanism against overexcitation of photosystem II, triggered by excess ΔpH in photosynthetic membranes. The light-harvesting complexes (LHCs), the de-epoxidation of violaxanthin to zeaxanthin, and the photosystem II subunit S (PsbS) work in synergy for an optimized multilevel response. Understanding the fine details of this synergy has proven challenging to scientific research. Here, we employ large-scale, all-atom molecular simulations and beyond experimental insight, we proceed a step further in identifying the PsbS dynamics that could possibly be associated with this synergy. For the first time, to our knowledge, we probe the distinct behavior of PsbS under ΔpH that probes the details of the potential dimer-to-monomer transition, and in a violaxanthin/zeaxanthin-rich membrane, at an all-atom resolution. We propose that the lumen-exposed residues, threonine 162 and glutamic acid 173, form stabilizing hydrogen bonds between the PsbS monomers only at high lumen pH, whereas at low pH (excess ΔpH) this interaction is lost, and leads to higher flexibility of the protein and potentially to the dimer-to-monomer transition. Lastly, we discuss how conformational changes under the presence of ΔpH/zeaxanthin are related to the PsbS role in the current nonphotochemical quenching model in the literature. For the latter, we probe a PsbS-monomeric LHCII association. The association is proposed to potentially alter the monomeric LHCII sensitivity to ΔpH by changing the pKa values of interacting LHCII residues. This serves as an example where protonation-ligation events enhance protein-protein interactions fundamental to many life processes.
[Mh] Termos MeSH primário: Modelos Moleculares
Complexo de Proteína do Fotossistema II/química
Complexo de Proteína do Fotossistema II/metabolismo
Estresse Fisiológico
[Mh] Termos MeSH secundário: Multimerização Proteica
Estrutura Quaternária de Proteína
Xantofilas/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Photosystem II Protein Complex); 0 (Xanthophylls)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180210
[Lr] Data última revisão:
180210
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171207
[St] Status:MEDLINE


  4 / 6295 MEDLINE  
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[PMID]:29191002
[Au] Autor:Nain-Perez A; Barbosa LCA; Maltha CRA; Giberti S; Forlani G
[Ad] Endereço:Department of Chemistry, Universidade Federal de Minas Gerais , Av. Pres. Antônio Carlos, 6627, Campus Pampulha, CEP 31270-901, Belo Horizonte, MG Brazil.
[Ti] Título:Tailoring Natural Abenquines To Inhibit the Photosynthetic Electron Transport through Interaction with the D1 Protein in Photosystem II.
[So] Source:J Agric Food Chem;65(51):11304-11311, 2017 Dec 27.
[Is] ISSN:1520-5118
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Abenquines are natural N-acetylaminobenzoquinones bearing amino acid residues, which act as weak inhibitors of the photosynthetic electron transport chain. Aiming to exploit the abenquine scaffold as a model for the synthesis of new herbicides targeting photosynthesis, 14 new analogues were prepared by replacing the amino acid residue with benzylamines and the acetyl with different acyl groups. The synthesis was accomplished in three steps with a 68-95% overall yield from readily available 2,5-dimethoxyaniline, acyl chlorides, and benzyl amines. Key steps include (i) acylation of the aniline, (ii) oxidation, and (iii) oxidative addition of the benzylamino moiety. The compounds were assayed for their activity as Hill inhibitors, under basal, uncoupled, or phosphorylating conditions, or excluding photosystem I. Four analogues showed high effectiveness (IC = 0.1-0.4 µM), comparable with the commercial herbicide diuron (IC = 0.3 µM). The data suggest that this class of compounds interfere at the reducing side of photosystem II, having protein D1 as the most probable target. Molecular docking studies with the plastoquinone binding site of Spinacia oleracea further strengthened this proposal.
[Mh] Termos MeSH primário: Benzoquinonas/farmacologia
Transporte de Elétrons/efeitos dos fármacos
Herbicidas/farmacologia
Fotossíntese/efeitos dos fármacos
Complexo de Proteína do Fotossistema II/metabolismo
Spinacia oleracea/metabolismo
[Mh] Termos MeSH secundário: Benzoquinonas/química
Cloroplastos/efeitos dos fármacos
Cloroplastos/metabolismo
Herbicidas/química
Simulação de Acoplamento Molecular
Spinacia oleracea/efeitos dos fármacos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Benzoquinones); 0 (Herbicides); 0 (Photosystem II Protein Complex)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180108
[Lr] Data última revisão:
180108
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171202
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jafc.7b04624


  5 / 6295 MEDLINE  
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[PMID]:29262360
[Au] Autor:Van Eerden FJ; Melo MN; Frederix PWJM; Marrink SJ
[Ad] Endereço:Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, the Netherlands. Electronic address: floris@vaneerden.eu.
[Ti] Título:Prediction of Thylakoid Lipid Binding Sites on Photosystem II.
[So] Source:Biophys J;113(12):2669-2681, 2017 Dec 19.
[Is] ISSN:1542-0086
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The thylakoid membrane has a unique lipid composition, consisting mostly of galactolipids. These thylakoid lipids have important roles in photosynthesis. Here, we investigate to what extent these lipids bind specifically to the Photosystem II complex. To this end, we performed coarse-grain MD simulations of the Photosystem II complex embedded in a thylakoid membrane with realistic composition. Based on >85 µs simulation time, we find that monogalactosyldiacylglycerol and sulfoquinovosyldiacylglycerol lipids are enriched in the annular shell around the protein, and form distinct binding sites. From the analysis of residue contacts, we conclude that electrostatic interactions play an important role in stabilizing these binding sites. Furthermore, we find that chlorophyll a has a prevalent role in the coordination of the lipids. In addition, we observe lipids to diffuse in and out of the plastoquinone exchange cavities, allowing exchange of cocrystallized lipids with the bulk membrane and suggesting a more open nature of the plastoquinone exchange cavity. Together, our data provide a wealth of information on protein-lipid interactions for a key protein in photosynthesis.
[Mh] Termos MeSH primário: Lipídeos de Membrana/metabolismo
Simulação de Dinâmica Molecular
Complexo de Proteína do Fotossistema II/metabolismo
Tilacoides/metabolismo
[Mh] Termos MeSH secundário: Sítios de Ligação
Glicerol/metabolismo
Complexo de Proteína do Fotossistema II/química
Ligação Proteica
Conformação Proteica
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Membrane Lipids); 0 (Photosystem II Protein Complex); PDC6A3C0OX (Glycerol)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180102
[Lr] Data última revisão:
180102
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171221
[St] Status:MEDLINE


  6 / 6295 MEDLINE  
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[PMID]:29031439
[Au] Autor:Lian Z; Pan D; Wang W; Zhang D; Li G; Li H
[Ad] Endereço:Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, Shanghai Normal University, Shanghai 200234, China. Electronic address: zichao.lian.52c@st.kyoto-u.ac.jp.
[Ti] Título:Photoelectrocatalytic reduction of CO to methanol over a photosystem II-enhanced Cu foam/Si-nanowire system.
[So] Source:J Environ Sci (China);60:108-113, 2017 Oct.
[Is] ISSN:1001-0742
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:A solar-light double illumination photoelectrocatalytic cell (SLDIPEC) was fabricated for autonomous CO reduction and O evolution with the aid of photosystem II (PS-II, an efficient light-driven water-oxidized enzyme from nature) and utilized in a photoanode solution. The proposed SLPEC system was composed of Cu foam as the photoanode and p-Si nanowires (Si-NW) as the photocathode. Under solar irradiation, it exhibited a super-photoelectrocatalytic performance for CO conversion to methanol, with a high evolution rate (41.94mmol/hr), owing to fast electron transfer from PS-II to Cu foam. Electrons were subsequently trapped by Si-NW through an external circuit via bias voltage (0.5V), and a suitable conduction band potential of Si (-0.6eV) allowed CO to be easily reduced to CH OH at the photocathode. The constructed Z-scheme between Cu foam and Si-NW can allow the SLDIPEC system to reduce CO (8.03mmol/hr) in the absence of bias voltage. This approach makes full use of the energy band mismatch of the photoanode and photocathode to design a highly efficient device for solving environmental issues and producing clean energy.
[Mh] Termos MeSH primário: Dióxido de Carbono/química
Cobre/química
Metanol/química
Nanofios/química
Processos Fotoquímicos
Silício/química
[Mh] Termos MeSH secundário: Oxirredução
Complexo de Proteína do Fotossistema II
Energia Solar
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Photosystem II Protein Complex); 142M471B3J (Carbon Dioxide); 789U1901C5 (Copper); Y4S76JWI15 (Methanol); Z4152N8IUI (Silicon)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171019
[Lr] Data última revisão:
171019
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171017
[St] Status:MEDLINE


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[PMID]:29016622
[Au] Autor:Lamb JJ; Hohmann-Marriott MF
[Ad] Endereço:Department of Biotechnology & PhotoSynLab, NTNU, Trondheim, Norway.
[Ti] Título:Manganese acquisition is facilitated by PilA in the cyanobacterium Synechocystis sp. PCC 6803.
[So] Source:PLoS One;12(10):e0184685, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Manganese is an essential element required by cyanobacteria, as it is an essential part of the oxygen-evolving center of photosystem II. In the presence of atmospheric oxygen, manganese is present as manganese oxides, which have low solubility and consequently provide low bioavailability. It is unknown if cyanobacteria are able to utilize these manganese sources, and what mechanisms may be employed to do so. Recent evidence suggests that type IV pili in non-photosynthetic bacteria facilitate electron donation to extracellular electron acceptors, thereby enabling metal acquisition. Our present study investigates whether PilA1 (major pilin protein of type IV pili) enables the cyanobacterium Synechocystis PCC 6808 to access to Mn from manganese oxides. We present physiological and spectroscopic data, which indicate that the presence of PilA1 enhances the ability of cyanobacteria to grow on manganese oxides. These observations suggest a role of PilA1-containing pili in cyanobacterial manganese acquisition.
[Mh] Termos MeSH primário: Cianobactérias/genética
Proteínas de Fímbrias/genética
Fímbrias Bacterianas/metabolismo
Manganês/metabolismo
[Mh] Termos MeSH secundário: Cianobactérias/crescimento & desenvolvimento
Cianobactérias/metabolismo
Proteínas de Fímbrias/metabolismo
Fímbrias Bacterianas/genética
Compostos de Manganês/metabolismo
Óxidos/metabolismo
Oxigênio/metabolismo
Complexo de Proteína do Fotossistema II/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Manganese Compounds); 0 (Oxides); 0 (Photosystem II Protein Complex); 147680-16-8 (Fimbriae Proteins); 42Z2K6ZL8P (Manganese); 64J2OA7MH3 (manganese oxide); S88TT14065 (Oxygen)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171031
[Lr] Data última revisão:
171031
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171011
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0184685


  8 / 6295 MEDLINE  
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[PMID]:28862739
[Au] Autor:Nagao R; Suzuki T; Dohmae N; Shen JR; Tomo T
[Ad] Endereço:Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Japan.
[Ti] Título:Functional role of Lys residues of Psb31 in electrostatic interactions with diatom photosystem II.
[So] Source:FEBS Lett;591(20):3259-3264, 2017 Oct.
[Is] ISSN:1873-3468
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:We recently revealed that positively charged amino acids of Psb31, an extrinsic subunit found in diatom photosystem II (PSII), are involved in electrostatic interactions with PSII intrinsic subunits. However, the molecular interactions of Psb31 with PSII remain unclear. Here, we report the functional contribution of Lys residues in the binding of Psb31 to PSII using site-directed mutants of Psb31. Each of the K33A, K39A, K54A, K56A, K57A, and K69A mutants exhibits decreased binding affinities to PSII concomitantly with decreases in the O evolution activity. Conversely, each of the K24A, K76A, K80A, and K117A mutants functionally binds to PSII in a manner similar to wild-type Psb31. These results provide evidence that some Lys residues of Psb31 are responsible for electrostatic interactions with PSII.
[Mh] Termos MeSH primário: Alanina/química
Diatomáceas/enzimologia
Lisina/química
Complexo de Proteína do Fotossistema II/química
Subunidades Proteicas/química
[Mh] Termos MeSH secundário: Alanina/metabolismo
Sequência de Aminoácidos
Substituição de Aminoácidos
Sítios de Ligação
Clonagem Molecular
Cristalografia por Raios X
Diatomáceas/genética
Escherichia coli/genética
Escherichia coli/metabolismo
Expressão Gênica
Cinética
Complexos de Proteínas Captadores de Luz/química
Complexos de Proteínas Captadores de Luz/metabolismo
Lisina/metabolismo
Modelos Moleculares
Mutação
Complexo de Proteína do Fotossistema II/genética
Complexo de Proteína do Fotossistema II/metabolismo
Ligação Proteica
Domínios e Motivos de Interação entre Proteínas
Estrutura Secundária de Proteína
Subunidades Proteicas/genética
Subunidades Proteicas/metabolismo
Proteínas Recombinantes/química
Proteínas Recombinantes/genética
Proteínas Recombinantes/metabolismo
Alinhamento de Sequência
Homologia de Sequência de Aminoácidos
Eletricidade Estática
[Pt] Tipo de publicação:LETTER
[Nm] Nome de substância:
0 (Light-Harvesting Protein Complexes); 0 (Photosystem II Protein Complex); 0 (Protein Subunits); 0 (Recombinant Proteins); 127137-94-4 (photosystem II, chlorophyll-binding protein, CP-47); K3Z4F929H6 (Lysine); OF5P57N2ZX (Alanine)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171031
[Lr] Data última revisão:
171031
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170902
[St] Status:MEDLINE
[do] DOI:10.1002/1873-3468.12830


  9 / 6295 MEDLINE  
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[PMID]:28850005
[Au] Autor:de Almeida ACG; Petersen K; Langford K; Thomas KV; Tollefsen KE
[Ad] Endereço:a Norwegian Institute for Water Research , Oslo , Norway.
[Ti] Título:Mixture toxicity of five biocides with dissimilar modes of action on the growth and photosystem II efficiency of Chlamydomonas reinhardtii.
[So] Source:J Toxicol Environ Health A;80(16-18):971-986, 2017.
[Is] ISSN:1528-7394
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Biocides are extensively used and universally distributed. Some are highly toxic to algae, including antifoulants, herbicides, and fungicides. The inhibition of algal growth is an important regulatory endpoint for toxicity assessment of single compounds. However, in the aquatic environment, mixtures of compounds with unknown toxicities and mode of action (MoA) co-exist, making single toxicity assessment inadequate to ensure protection of the aquatic environment. This study aimed to characterize the combined toxicity of five environmentally relevant biocides-aclonifen, bifenox, dichlofluanid, metribuzin, and triclosan-with different MoA on growth and photosystem (PS) II efficiency of Chlamydomonas reinhardtii. For growth inhibition, herbicides bifenox and metribuzin were the most toxic, whereas triclosan was least. Only aclonifen and metribuzin exerted a significant effect on PSII, which was also correlated with reduced algal growth. The combined effect of the five biocides on growth inhibition was predominantly additive and presumed to act by independent MoA with potential antagonism observed only at low concentrations and at shorter duration of exposure. The binary mixture of metribuzin and aclonifen exhibited additive effects on diminished PSII efficiency, and effects were apparently induced by an independent MoA. Potential synergy of this mixture on growth inhibition was identified at the highest concentrations. Growth inhibition was found to be a more valuable endpoint for regulatory studies than PSII inhibition due to its environmental relevance, integration of multiple MoA and sensitivity.
[Mh] Termos MeSH primário: Chlamydomonas reinhardtii/efeitos dos fármacos
Desinfetantes/toxicidade
Complexo de Proteína do Fotossistema II/metabolismo
Poluentes Químicos da Água/toxicidade
[Mh] Termos MeSH secundário: Compostos de Anilina/toxicidade
Chlamydomonas reinhardtii/crescimento & desenvolvimento
Determinação de Ponto Final
Herbicidas/toxicidade
Éteres Fenílicos/toxicidade
Testes de Toxicidade
Triazinas/toxicidade
Triclosan/toxicidade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Aniline Compounds); 0 (Disinfectants); 0 (Herbicides); 0 (Phenyl Ethers); 0 (Photosystem II Protein Complex); 0 (Triazines); 0 (Water Pollutants, Chemical); 1762RDA835 (aclonifen); 4NM5039Y5X (Triclosan); 76A92XU36Y (dichlofluanid); KSB85XT26Y (bifenox); QO836138OV (metribuzin)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171031
[Lr] Data última revisão:
171031
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170830
[St] Status:MEDLINE
[do] DOI:10.1080/15287394.2017.1352176


  10 / 6295 MEDLINE  
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[PMID]:28750320
[Au] Autor:Taira H; Taguchi S
[Ad] Endereço:Laboratory of Biological Oceanography, Soka University, 1-236 Tangi-Cho, Hachioji, Tokyo 192-8857, Japan.
[Ti] Título:Cellular Mycosporine-like amino acids protect photosystem II of the Dinoflagellate Scrippsiella sweeneyae from ultraviolet radiation damage.
[So] Source:J Photochem Photobiol B;174:27-34, 2017 Sep.
[Is] ISSN:1873-2682
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:Photo-damage to photosystem II (PSII) from ultraviolet radiation (UVR) was determined using chlorophyll fluorescence in relation to sunscreen factors on the dinoflagellate Scrippsiella sweeneyae based on the cellular mycosporine-like amino acid contents (C ) and cell diameter (=light path, d). Three different C were prepared by acclimating cells to three levels (30.8, 15.2, and 7.7Wm ) of photosynthetically active radiation (PAR). PAR-acclimated cells were exposed to PAR (0.64Wm )+UVR (3.94W m =2.51Wm UVB+1.43Wm UVA) for 12min. High PAR (HL) and medium PAR (NDF1) treatments acclimated cells to induce shinorine and porphyra-334 (longer λ at 333 and 334nm); whereas, the low PAR (NDF2) treatment acclimated cells to induce mycosporine-glycine and palythine (shorter λ at 310 and 320nm). Absorption spectra for the individual MAAs were reconstructed using the λ and C and were summed to reconstruct the absorption of the total C (m cell ) to estimate the sunscreen factor (S ) at λ . The highest S was obtained for cells that acclimated to the highest PAR (highest C and longest d); whereas, the lowest S was obtained for cells acclimated to the lowest PAR (the lowest C and the shortest d). C contributed approximately 94%, whereas d contributed <6%, of the sunscreen factor (S ). UVR-induced damage was indexed with a temporal decrease in the optimum quantum yield (F /F ) in the Photosystem II. The highest damage was observed for cells acclimated to the lowest S (lowest C and shortest d); whereas, the lowest damage was observed for cells acclimated to the highest S (highest C and longest d). The C mitigated most of the UVR-induced damage in photosystem II of the dinoflagellate S. sweeneyae.
[Mh] Termos MeSH primário: Aminoácidos/metabolismo
Dinoflagelados/metabolismo
Dinoflagelados/efeitos da radiação
Complexo de Proteína do Fotossistema II/metabolismo
Raios Ultravioleta/efeitos adversos
[Mh] Termos MeSH secundário: Clorofila/metabolismo
Dinoflagelados/citologia
Fotossíntese/efeitos da radiação
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Amino Acids); 0 (Photosystem II Protein Complex); 1406-65-1 (Chlorophyll); YF5Q9EJC8Y (chlorophyll a)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171012
[Lr] Data última revisão:
171012
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170728
[St] Status:MEDLINE



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