64 results on '"Bouzon ZL"'
Search Results
2. Exacerbation of DSS-induced colitis in mice lacking kinin B1 receptors through compensatory up-regulation of kinin B2 receptors: the role of tight junctions and intestinal homeostasis
- Author
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Marcon, R, Claudino, RF, Dutra, RC, Bento, AF, Schmidt, EC, Bouzon, ZL, Sordi, R, Morais, RLT, Pesquero, JB, and Calixto, JB
- Subjects
Themed Section: Endothelin ,Male ,Mice, Knockout ,Sulfonamides ,Receptor, Bradykinin B2 ,Dextran Sulfate ,Dioxoles ,Bradykinin ,Colitis ,Receptor, Bradykinin B1 ,Tight Junctions ,Up-Regulation ,Bradykinin B1 Receptor Antagonists ,Intestines ,Mice, Inbred C57BL ,Mice ,Bradykinin B2 Receptor Antagonists ,Animals ,Cytokines ,Homeostasis ,Intestinal Mucosa ,Peroxidase - Abstract
Kinins are pro-inflammatory peptides that are released during tissue injury, including that caused by inflammatory bowel disease. Herein, we assessed the role and underlying mechanisms through which the absence of kinin B(1) receptors exacerbates the development of dextran sulfate sodium (DSS)-induced colitis in mice.B(1) and B(2) receptor antagonists and B(1) receptor knockout mice (B1(-/-) ) were used to assess the involvement of B(1) and B(2) receptor signalling in a DSS-colitis. B(1) receptor, B(2) receptor, occludin and claudin-4 expression, cytokine levels and cell permeability were evaluated in colon from wild-type (WT) and B1(-/-) mice.DSS-induced colitis was significantly exacerbated in B1(-/-) compared with WT mice. IL-1β, IFN-γ, keratinocyte-derived chemokine and macrophage inflammatory protein-2 were markedly increased in the colon from DSS-treated B1(-/-) compared with DSS-treated WT mice. Treatment of WT mice with a selective B(1) receptor antagonist, DALBK or SSR240612, had no effect on DSS-induced colitis. Of note, B(2) receptor mRNA expression was significantly up-regulated in colonic tissue from the B1(-/-) mice after DSS administration. Moreover, treatment with a selective B(2) receptor antagonist prevented the exacerbation of colitis in B1(-/-) mice following DSS administration. The water- or DSS-treated B1(-/-) mice showed a decrease in occludin gene expression, which was partially prevented by the B(2) receptor antagonist.A loss of B(1) receptors markedly exacerbates the severity of DSS-induced colitis in mice. The increased susceptibility of B1(-/-) may be associated with compensatory overexpression of B(2) receptors, which, in turn, modulates tight junction expression.
- Published
- 2012
3. Exacerbation of DSS-induced colitis in mice lacking kinin B1receptors through compensatory up-regulation of kinin B2receptors: the role of tight junctions and intestinal homeostasis
- Author
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Marcon, R, primary, Claudino, RF, additional, Dutra, RC, additional, Bento, AF, additional, Schmidt, EC, additional, Bouzon, ZL, additional, Sordi, R, additional, Morais, RLT, additional, Pesquero, JB, additional, and Calixto, JB, additional
- Published
- 2012
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4. Exacerbation of DSS-induced colitis in mice lacking kinin B1 receptors through compensatory up-regulation of kinin B2 receptors: the role of tight junctions and intestinal homeostasis.
- Author
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Marcon, R, Claudino, RF, Dutra, RC, Bento, AF, Schmidt, EC, Bouzon, ZL, Sordi, R, Morais, RLT, Pesquero, JB, and Calixto, JB
- Subjects
DISEASE exacerbation ,DEXTRAN sulfate ,COLITIS ,LABORATORY mice ,KININS ,TIGHT junctions ,HOMEOSTASIS ,INFLAMMATORY bowel diseases - Abstract
Background and Purpose Kinins are pro-inflammatory peptides that are released during tissue injury, including that caused by inflammatory bowel disease. Herein, we assessed the role and underlying mechanisms through which the absence of kinin B
1 receptors exacerbates the development of dextran sulfate sodium ( DSS)-induced colitis in mice. Experimental Approach B1 and B2 receptor antagonists and B1 receptor knockout mice ( B1−/− ) were used to assess the involvement of B1 and B2 receptor signalling in a DSS-colitis. B1 receptor, B2 receptor, occludin and claudin-4 expression, cytokine levels and cell permeability were evaluated in colon from wild-type ( WT) and B1−/− mice. Key Results DSS-induced colitis was significantly exacerbated in B1−/− compared with WT mice. IL-1β, IFN-γ, keratinocyte-derived chemokine and macrophage inflammatory protein-2 were markedly increased in the colon from DSS-treated B1−/− compared with DSS-treated WT mice. Treatment of WT mice with a selective B1 receptor antagonist, DALBK or SSR240612, had no effect on DSS-induced colitis. Of note, B2 receptor mRNA expression was significantly up-regulated in colonic tissue from the B1−/− mice after DSS administration. Moreover, treatment with a selective B2 receptor antagonist prevented the exacerbation of colitis in B1−/− mice following DSS administration. The water- or DSS-treated B1−/− mice showed a decrease in occludin gene expression, which was partially prevented by the B2 receptor antagonist. Conclusions and Implications A loss of B1 receptors markedly exacerbates the severity of DSS-induced colitis in mice. The increased susceptibility of B1−/− may be associated with compensatory overexpression of B2 receptors, which, in turn, modulates tight junction expression. [ABSTRACT FROM AUTHOR]- Published
- 2013
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5. Changes in xylem morphology and activity of defense-related enzymes are associated with bean resistance during Fusarium oxysporum colonization.
- Author
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Garcés-Fiallos FR, de Quadros FM, Ferreira C, de Borba MC, Bouzon ZL, Barcelos-Oliveira JL, and Stadnik MJ
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- Disease Resistance genetics, Plant Diseases genetics, Xylem, Fabaceae, Fusarium
- Abstract
Genetic resistance is the main strategy to control Fusarium wilt in common bean. Despite this, few studies have focused on defense mechanisms involved in bean resistance to Fusarium oxysporum f. sp. phaseoli (Fop). Thus, the present study aimed to investigate the changes in xylem morphology and involvement of phenylpropanoid compounds and their biosynthetic enzymes in bean resistance against Fop. Uirapuru and UFSC-01 genotypes characterized, respectively, as susceptible and resistant were used. In roots and hypocotyls, guaiacol peroxidase (GPX), phenylalanine ammonia-lyase (PAL), and polyphenol oxidase (PPO) activities were determined at 0, 1, 2, 3, 4, 5, and 6 days after inoculation (dai), and flavonoids, total phenolics, and lignin content were quantified at 0, 3, and 6 dai. Cross sections of taproots and hypocotyls were examined under epifluorescence (at 1, 3, and 6 dai) and transmission electron (at 6 dai) microscopic to analyze the morphology of xylem cell walls. Overall, there was an increase in the activity of all studied enzymes in resistant bean plants, mainly during advanced colonization stages. Modifications in xylem morphology were more intense in roots of resistant genotype resulting in an increase of occluded cells, organelles, and cell wall strengthening. This study provides evidence that bean resistance is associated with increased phenylpropanoid enzymatic activity and cell wall reinforcement of some xylem cells., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)
- Published
- 2022
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6. Updating embryonic ontogenesis in Araucaria angustifolia: from Burlingame (1915) to the present.
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Goeten D, Rogge-Renner GD, Schmidt ÉC, Bouzon ZL, Farias-Soares FL, Guerra MP, and Steiner N
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- History, 20th Century, History, 21st Century, Araucaria chemistry, Pollen embryology
- Abstract
This study addresses gaps in our understanding of pre-fertilization and archegonia development and reinterprets embryonic ontogenesis from Burlingame (Bot Gaz 59:1-39, 1915) to the present based on timescale and structural features allowing us to determine functionally and developmentally accurate terminology for all these stages in A. angustifolia. Different from previous reports, only after pollination, pre-fertilization tissue development occurs (0-13 months after pollination (MAP)) and gives rise to a mature megagametophyte. During all this period, pollen is in a dormant state at the microphyla, and pollen tube germination in nucellus tissue is only observed at the stage of archegonia formation (13 MAP) and not at the free nuclei stage as reported before. For the first time, 14 months after pollination, a fertilization window was indicated, and at 15 MAP, the polyzygotic polyembryony from different archegonia was also seen. After that, subordinated proembryo regression occurs and at least three embryonic developmental stages of dominant embryo were characterized: proembryogenic, early embryogenic, and late embryogenic (15-23 MAP). Along these stages, histochemical and ultrastructural analyses suggest the occurrence of cell death in suspensor and in cap cells of dominant embryo that was not previously reported. The differentiation of meristems, procambium, pith, and cortex tissues in late embryogenic stage was detailed. The morphohistological characterization of pre-fertilization and embryonic stages, together with the timescale of megastrobili development, warranted a referential map of female reproductive structure in this species.
- Published
- 2020
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7. Cellular Responses of Gelidium floridanum (Gelidiales, Rhodophyta) Tetraspores Under Heat Wave and Copper Pollution.
- Author
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Kreusch M, Poltronieri E, Bouvie F, Pereira DT, Batista D, Ramlov F, Maraschin M, Bouzon ZL, and Simioni C
- Subjects
- Hot Temperature, Photosynthesis, Seawater, Temperature, Copper, Rhodophyta
- Abstract
Spore settlement and development are bottlenecks for resilience of habitat-forming macroalgal species. These processes are directly related to temperature, a global stressor protagonist of ocean warming. The toxic effects of local pollutants such as copper may be worsened under a global warming scenario. Therefore, in this paper, we investigated the effects of increased temperature combined with elevated concentrations of copper on the viability, photosynthetic pigments, and ultrastructure of Gelidium floridanum tetraspores. Tetraspores were cultivated on slides with sterilized seawater or seawater enriched with CuCl
2 , and incubated under 24°C or 30°C for 24 h. Tetraspores cultivated with copper 3.0 μM under 30°C had lower viability. Both temperature and copper had a significant effect on phycocyanin and phycoerythrin concentrations. Samples cultivated with copper under 30°C presented a heavily altered cellular structure, with vesicles throughout the cytoplasm, chloroplasts with altered structure and cells with degenerated cytoplasm and cell walls. Our findings show that temperature and copper significantly affect the viability, photosynthetic pigments, and ultrastructure of G. floridanum tetraspores, presenting an additive interaction for the physiology of this seaweed's early stages., (© 2019 Phycological Society of America.)- Published
- 2019
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8. Effects of Ultraviolet Radiation (UV-A+UV-B) on the Antioxidant Metabolism of the Red Macroalga Species Acanthophora spicifera (Rhodophyta, Ceramiales) From Different Salinity and Nutrient Conditions.
- Author
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Pereira DT, Pereira B, Fonseca A, Ramlov F, Maraschin M, Álvarez-Gómez F, Figueroa FL, Schmidt ÉC, Bouzon ZL, and Simioni C
- Subjects
- Water chemistry, Antioxidants metabolism, Ecosystem, Rhodophyta metabolism, Rhodophyta radiation effects, Salinity, Ultraviolet Rays
- Abstract
Acanthophora spicifera (M.Vahl) Børgesen is a macroalga of great economic importance. This study evaluated the antioxidant responses of two algal populations of A. spicifera adapted to different abiotic conditions when exposed to ultraviolet-A+ultraviolet-B radiation (UV-A+UV-B). Experiments were performed using the water at two collection points for 7 days of acclimatization and 7 days of exposure to UVR (3 h per day), followed by metabolic analyses. At point 1, water of 30 ± 1 practical salinity unit (psu) had concentrations of 1.06 ± 0.27 mm NH 4 + , 8.47 ± 0.01 mm NO 3 - , 0.17 ± 0.01 mm PO 4 - 3 and pH 7.88. At point 2, water of 35 ± 1 psu had concentrations of 1.13 ± 0.05 mm NH 4 + , 3.73 ± 0.01 mm NO 3 - , 0.52 ± 0.01 mm PO 4 - 3 and pH 8.55. Chlorophyll a, phycobiliproteins, carotenoids, mycosporins, polyphenolics and antioxidant enzymes (catalase, superoxide dismutase and guaiacol peroxidase) were evaluated. The present study demonstrates that ultraviolet radiation triggers antioxidant activity in the A. spicifera. However, such activation resulted in greater responses in samples of the point 1, with lower salinity and highest concentration of nutrients., (© 2019 American Society for Photobiology.)
- Published
- 2019
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9. Effects of Ultraviolet Radiation (UVA + UVB) on Germination of Carpospores of the Red Macroalga Pyropia acanthophora var. brasiliensis (Rhodophyta, Bangiales): Morphological Changes.
- Author
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Pereira DT, Batista D, Filipin EP, Bouzon ZL, and Simioni C
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- Chloroplasts metabolism, Cytoplasm metabolism, Microscopy, Confocal, Microscopy, Electron, Transmission, Reactive Oxygen Species metabolism, Rhodophyta growth & development, Rhodophyta metabolism, Germination radiation effects, Rhodophyta radiation effects, Ultraviolet Rays
- Abstract
Carpospores of Pyropia acanthophora var. brasiliensis are dispersion and reproduction units responsible for giving rise to the diploid filamentous structure of this alga's life cycle. The present study assesses the anthropogenic impact of ultraviolet radiation (UVR) on morphology and ultrastructure, spore viability, autofluorescence of chloroplasts and the amount of intensity of ROS during the germination of carpospores. Carpospores were cultivated at 24 ± 1°C, 40 ± 10 μmol photons m
-2 s-1 with photoperiod of 12 h and exposed to UVAR + UVBR for 3 h a day for 2 days with a daily dose of 5.05 J cm-2 for UVAR and 0.095 J cm-2 for UVBR. Samples were cultured for another five days exposed only to PAR in order to confirm their viability after the initial 2-day exposure. Carpospores showed significant sensitivity to UVR exposure after only 48 h, including changes in developmental rate, overall morphology, cell organization and chloroplast autofluorescence. UVR exposure inhibited germ tube formation in carpospores, which were mostly nonviable and/or altered, showing retracted cytoplasm and disorganized cytoplasmic content. Even in the absence of UVR exposure, carpospores remained collapsed, indicating irreversible damage. It can be concluded that UVR is a limiting factor for the development of P. acanthophora., (© 2018 The American Society of Photobiology.)- Published
- 2019
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10. Participation of actin filaments, myosin and phosphatidylinositol 3-kinase in the formation and polarisation of tetraspore germ tube of Gelidium floridanum (Rhodophyta, Florideophyceae).
- Author
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Filipin EP, Pereira DT, Ouriques LC, Bouzon ZL, and Simioni C
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- Bridged Bicyclo Compounds, Heterocyclic pharmacology, Cell Wall metabolism, Chloroplasts metabolism, Chromones pharmacology, Cytochalasins, Diacetyl analogs & derivatives, Diacetyl pharmacology, Morpholines pharmacology, Phosphoinositide-3 Kinase Inhibitors, Plant Structures growth & development, Plant Structures metabolism, Rhodophyta drug effects, Rhodophyta growth & development, Thiazolidines pharmacology, Actin Cytoskeleton metabolism, Myosins metabolism, Phosphatidylinositol 3-Kinase metabolism, Rhodophyta metabolism
- Abstract
This study aimed to examine the evidence of direct interaction among actin, myosin and phosphatidylinositol 3-kinase (PI3K) in the polarisation and formation of the tetraspore germ tube of Gelidium floridanum. After release, tetraspores were exposed to cytochalasin B, latrunculin B, LY294002 and BDM for a period of 6 h. In control samples, formation of the germ tube occurred after the experimental period, with cellulose formation and elongated chloroplasts moving through the tube region in the presence of F-actin. In the presence of cytochalasin B, an inhibitor of F-actin, latrunculin B, an inhibitor of G-actin, and BDM, a myosin inhibitor, tetraspores showed no formation of the germ tube or cellulose. Spherical-shaped chloroplasts were observed in the central region with a few F-actin filaments in the periphery of the cytoplasm. Tetraspores treated with LY294002, a PI3K inhibitor, showed no formation of the tube at the highest concentrations. Polarisation of cytoplasmic contents did not occur, only cellulose formation. It was concluded that F-actin directs the cell wall components and contributes to the maintenance of chloroplast shape and elongation during germ tube formation. PI3K plays a fundamental role in signalling for the asymmetric polarisation of F-actin. Thus, F-actin regulates the polarisation and germination processes of tetraspores of G. floridanum., (© 2018 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.)
- Published
- 2019
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11. Ocean warming and copper pollution: implications for metabolic compounds of the agarophyte Gelidium floridanum (Gelidiales, Rhodophyta).
- Author
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Kreusch M, Poltronieri E, Bouvie F, Batista D, Pereira DT, Ramlov F, Maraschin M, Bouzon ZL, Schmidt ÉC, and Simioni C
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- Climate Change, Hot Temperature, Oceans and Seas, Rhodophyta growth & development, Copper adverse effects, Global Warming, Pigments, Biological metabolism, Rhodophyta metabolism, Seawater chemistry, Water Pollutants, Chemical adverse effects
- Abstract
Ocean warming is increasing and scientific predictions suggest a rise of up to 4°C in sea water temperatures. The combination of a polluted and warmer environment may be detrimental for aquatic species, especially for primary producers such as seaweeds. This study investigated the potential for interactive effects of an increased seawater temperature in a copper-rich environment on the photosynthetic pigments and metabolic compounds of the red seaweed Gelidium floridanum. Seaweed samples were cultivated in a factorial design with temperature (24°C and 30°C), copper (0 and 3 μM), and time (7 and 14 d). The exposure of G. floridanum to copper and 30°C for 7 d resulted in a lower concentration of chlorophyll a, smaller phycobiliprotein rods and lower concentration of soluble sugars. After 14 d of cultivation, a higher concentration of chlorophyll a and soluble sugars could be observed on seaweeds cultivated under 30°C. The accumulation of carotenoids and the release of phenolic compounds indicated specific protective mechanisms against temperature and copper, respectively. Overall, seaweeds grew less when exposed to copper 3 μM at 30°C., (© 2018 Phycological Society of America.)
- Published
- 2018
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12. Halimeda jolyana (Bryopsidales, Chlorophyta) presents higher vulnerability to metal pollution at its lower temperature limits of distribution.
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Scherner F, Bastos E, Rover T, de Medeiros Oliveira E, Almeida R, Itokazu AG, Bouzon ZL, Rörig LR, Pereira SMB, and Horta PA
- Subjects
- Biomass, Chloroplasts, Cold Temperature, Hot Temperature, Photosynthesis, Temperature, Chlorophyta drug effects, Metals toxicity, Seaweed drug effects, Water Pollutants toxicity
- Abstract
Seaweeds living at their temperature limits of distribution are naturally exposed to physiological stressors, facing additional stress when exposed to coastal pollution. The physiological responses of seaweeds to environmental conditions combining natural and anthropogenic stressors provide important information on their vulnerability. We assessed the physiological effects and ultrastructural alterations of trace metals enrichment at concentrations observed in polluted regions within the temperature ranges of distribution of the endemic seaweed Halimeda jolyana, an important component of tropical southwestern Atlantic reefs. Biomass yield and photosynthetic performance declined substantially in samples exposed to metal, although photosynthesis recovered partially at the highest temperature when metal enrichment was ceased. Metal enrichment caused substantial ultrastructural alterations to chloroplasts regardless of temperatures. The lack of photosynthetic recovery at the lower temperatures indicates a higher vulnerability of the species at its temperature limits of distribution in the southwestern Atlantic.
- Published
- 2018
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13. Tadpoles fed supplemented diet with probiotic bacterium isolated from the intestinal tract of bullfrog Lithobates catesbeianus: Haematology, cell activity and electron microscopy.
- Author
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Pereira SA, Jerônimo GT, Marchiori NC, Oliveira HM, Jesus GFA, Schmidt EC, Bouzon ZL, Vieira FN, Martins ML, and Mouriño JLP
- Subjects
- Animal Feed analysis, Animals, Dietary Supplements analysis, Hematology, Intestines growth & development, Intestines microbiology, Intestines ultrastructure, Lactobacillus classification, Lactobacillus genetics, Lactobacillus growth & development, Lactobacillus isolation & purification, Larva growth & development, Larva microbiology, Larva ultrastructure, Microscopy, Electron, Rana catesbeiana blood, Rana catesbeiana growth & development, Larva metabolism, Probiotics administration & dosage, Rana catesbeiana microbiology
- Abstract
The aim of this study is to select and isolate autochthonous bacteria with probiotic potential for use in a supplemented diet for bullfrog tadpoles, Lithobates catesbeianus. A total of 20 strains of lactic acid bacteria were isolated. Nine out of these were used in the following in vitro assays: antagonism against pathogenic bacteria (ANT), antimicrobial activity from extracellular compounds (MIC), tolerance to bile salts (TBS), pH reduction, protease production, sensitivity to antimicrobial tetracycline, cell viability, growth rate and doubling time. Using these data was defined an ideotype (ideal strain) based on the best results. Distances were estimated with the Mahalanobis (D
2 ) test, and the best candidates, presenting the shortest ideotype distances, were considered to be used. The best strain was found to be Lactobacillus plantarum because it presented 10.00 ± 0.50 mm of ANT against Aeromonas hydrophila, 3.99 ± 0.01 of MIC independent of pathogenic bacteria, 85.07 ± 0.01 of TBS, 4.20 ± 0.02 of final pH, 17.67 ± 1.15 of protease production, 13.50 ± 2.00 sensitivity to antimicrobial tetracycline, 9.36 ± 0.04 of cell viability, 0.20 ± 0.00 of growth rate and 3.46 ± 0.00 doubling time. Therefore this probiotic candidate was then supplemented (2.045 ± 1.07 × 107 colony forming unities. g-1 ) into the diets of bullfrog tadpoles for a period of 42 days. At the end of the trial, samples of blood and intestines were collected to verify the haematological alterations and the intestinal morphology using transmission and scanning electron microscopy. Tadpoles fed the supplemented diet showed successful lactic acid bacterium colonisation, an increased number of circulating thrombocytes, monocytes, eosinophil and LG-PAS+ and also an increase in the length and density of intestinal microvilli. This study shows the feasibility of using probiotics isolated from farmed bullfrogs as a supplement in the diets of tadpoles, providing a promising alternative for modulating the health of these animals., (Copyright © 2017 Elsevier Ltd. All rights reserved.)- Published
- 2018
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14. Photosynthetic and ultrastructural responses of Ulva australis to Zn stress.
- Author
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Farias DR, Schmidt E, Simioni C, Bouzon ZL, Hurd CL, Eriksen RS, and Macleod CK
- Abstract
This research evaluated the effect of zinc (Zn) on the ultrastructure and the photosynthetic efficiency of a common green alga. Ulva australis was grown in the laboratory for 7days under a range of different Zn concentrations (0, 25, 50 and 100μgL
-1 ). Growth rate (Gr), photosynthetic efficiency (Fv/Fm and ETRmax), photosynthetic pigments, and metal accumulation were measured. Samples of 1mm length were taken to analyse the effect of Zn on the ultrastructure using transmission electron microscopy (TEM) and cytochemical responses (TB-O and PAS) were evaluated by light microscopy (LM). There were no significant differences in the growth rate, Fv/Fm, ETRmax and the photosynthetic pigments chlorophyll a, chlorophyll b and carotenoids (p>0.05) after 7days of Zn exposure. However, TEM revealed cytoplasm retraction, compression of cellulose fibrils, dissembled thylakoids and electron-dense bodies suggesting ultrastructural impacts from metal exposure and accumulation. Cytological analysis demonstrated that Zn affected U. australis cells at the three concentrations tested. The main effect was cytoplasm retraction and a decrease on the amount of starch granules, following exposure at 25μgL-1 and 50μgL-1 of Zn. We conclude that concentrations of Zn assessed in U. australis in this research has a short-term cellular effect as revealed by TEM and cytological analysis, demonstrating the importance of measuring a broad suite of endpoints to better understand species responses to environmentally relevant concentrations of Zn. However, U. australis was able to physiologically tolerate adverse conditions, since there was no effect on the photosynthetic performance and growth., (Copyright © 2017 Elsevier Ltd. All rights reserved.)- Published
- 2017
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15. Morphological and functional characterization of the hemocytes from the pearl oyster Pteria hirundo and their immune responses against Vibrio infections.
- Author
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Vieira GC, da Silva PM, Barracco MA, Hering AF, Albuquerque MCP, Coelho JDR, Schmidt ÉC, Bouzon ZL, Rosa RD, and Perazzolo LM
- Subjects
- Agglutination, Animals, Hemocytes immunology, Immunity, Cellular, Immunity, Humoral, Immunity, Innate, Ostreidae immunology, Vibrio physiology
- Abstract
Hemocyte populations of the pearl oyster Pteria hirundo were characterized at morphological, ultrastructural and functional levels. Three main hemocyte populations were identified: hyalinocytes, granulocytes and blast-like cells. Hyalinocytes were the most abundant population (88.2%) characterized by the presence of few or no granules in the cytoplasm and composed by two subpopulations, large and small hyalinocytes. Comparatively, granulocytes represented 2.2% of the hemocyte population and were characterized by the presence of numerous large electron-lucid granules in the cytoplasm. Finally, the blast-like cells (9.5%) were the smallest hemocytes, showing spherical shape and a high nucleus/cytoplasm ratio. Hemocytes exhibited a significant phagocytic capacity for inert particles (38.5%) and showed to be able to produce microbicidal molecules, such as reactive oxygen species (ROS) (ex vivo assays). The immune role of hemocytes was further investigated in the P. hirundo defense against the Gram-negative Vibrio alginolyticus. A significant decrease in the total number of hemocytes was observed at 24 h following injection of V. alginolyticus or sterile seawater (injury control) when compared to naïve (unchallenged) animals, indicating the migration of circulating hemocytes to the sites of infection and tissue damage. Bacterial agglutination was only observed against Gram-negative bacteria (Vibrio) but not against to marine Gram-positive-bacteria. Besides, an increase in the agglutination titer was observed against V. alginolyticus only in animals previously infected with this same bacterial strain. These results suggest that agglutinins or lectin-like molecules may have been produced in response to this particular microorganism promoting a specific recognition. The ultrastructural and functional characterization of P. hirundo hemocytes constitutes a new important piece of the molluscan immunity puzzle that can also contribute for the improvement of bivalve production sustainability., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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16. Effects of phenanthrene on early development of the Pacific oyster Crassostrea gigas (Thunberg, 1789).
- Author
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Nogueira DJ, Mattos JJ, Dybas PR, Flores-Nunes F, Sasaki ST, Taniguchi S, Schmidt ÉC, Bouzon ZL, Bícego MC, Melo CMR, Toledo-Silva G, and Bainy ACD
- Subjects
- Animal Shells drug effects, Animal Shells metabolism, Animals, Calcium metabolism, Crassostrea embryology, Crassostrea genetics, Embryo, Nonmammalian abnormalities, Embryo, Nonmammalian enzymology, Gene Expression drug effects, Larva, Phenanthrenes analysis, Seawater chemistry, Water Pollutants, Chemical analysis, Crassostrea drug effects, Embryo, Nonmammalian drug effects, Embryonic Development drug effects, Phenanthrenes toxicity, Water Pollutants, Chemical toxicity
- Abstract
Phenanthnere (PHE) is a polycyclic aromatic hydrocarbon continuously discarded in the marine environment and bioavailable to many aquatic species. Although studies about PHE toxicity have been documented for adult oysters, the effects on early developmental stages are poorly characterized in bivalves. In this study, the effects of PHE (0.02 and 2.0μg.L
-1 ) were evaluated on the embryogenesis and larval development of Crassostrea gigas. Toxicity bioassays, growth and deformities assessment, analysis of shell calcium abundance and transcript levels of genes related to xenobiotic biotransformation (CYP2AU2, CYP30C1), immune system (Cg-Tal) and tissue growth and shell formation (Ferritin, Insulin-like, Cg-Try, Calmodulin and Nacrein) were assayed in D-shape larvae after 24h of PHE exposure. At the highest concentration (2.0μg.L-1 ), PHE decreased the frequency of normal development (19.7±2.9%) and shell size (53.5±2.8mm). Developmental deformities were mostly related to abnormal mantle and shell formation. Lower calcium levels in oyster shells exposed to PHE 2.0μg.L-1 were observed, suggesting effects on shell structure. At this same PHE concentration, CYP30C1, Cg-Tal, Cg-Tyr, Calmodulin were upregulated and CYP2AU2, Ferritin, Nacrein, and Insulin-Like were downregulated compared to control larvae. At the lowest PHE concentration (0.02μg.L-1 ), it was observed a minor decrease in normal larval development (89,6±6%) and the remaining parameters were not affected. This is the first study to provide evidences that exposure to PHE can affect early oyster development at the molecular and morphological levels, possibly threatening this bivalve species., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2017
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17. The influence of salinity on growth, morphology, leaf ultrastructure, and cell viability of the seagrass Halodule wrightii Ascherson.
- Author
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Ferreira C, Simioni C, Schmidt ÉC, Ramlov F, Maraschin M, and Bouzon ZL
- Subjects
- Alismatales ultrastructure, Cell Survival, Plant Leaves ultrastructure, Salinity, Salt-Tolerant Plants growth & development, Salt-Tolerant Plants ultrastructure, Seawater, Alismatales growth & development, Plant Leaves growth & development
- Abstract
Halodule wrightii is an ecologically important seagrass; however, little is known about the adaptation of this species in the context of environmental change, particularly changes arising from alterations in salinity of coastal ecosystems. This study aimed to determine the effects of different salinities on growth, morphology, leaf ultrastructure, and cell viability of H. wrightii. To accomplish this, plants were cultivated for 21 days in salinities of 25, 35, and 45. More hydropotens were observed in samples exposed to salinity of 45 with increased invagination of the plasma membrane and cell wall. These invaginations were also observed in other epidermal cells of the leaf blade. In particular, a significant retraction of plasma membrane was seen in samples exposed to salinity of 45, with possible deposition of compounds between the membrane and cell wall. Osmotic stress in samples exposed to salinity of 45 affected the chloroplasts through an increase in plastoglobules and thylakoids by granum in the epidermal chloroplasts of the leaf and decrease in the number of chloroplasts. Overall, this study showed that H. wrightii can survive within salinities that range between 25 and 45 without changing growth rate. However, the plant did have higher cell viability at salinity of 35. Salt stress in mesocosms, at both salinity of 25 and 45, decreased cell viability in this species. H . wrightii had greater changes in salinity of 45; this showed that the species is more tolerant of salinities below this value.
- Published
- 2017
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18. Fine-tuning transmission electron microscopy methods to evaluate the cellular architecture of Ulvacean seaweeds (Chlorophyta).
- Author
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Farias DR, Simioni C, Poltronieri E, Bouzon ZL, and Macleod CK
- Subjects
- Cell Membrane ultrastructure, Chloroplasts ultrastructure, Formaldehyde pharmacology, Glutaral pharmacology, Osmium Tetroxide pharmacology, Polymers pharmacology, Chlorophyta ultrastructure, Microscopy, Electron, Transmission methods, Preservation, Biological methods, Seaweed ultrastructure, Tissue Fixation methods
- Abstract
Chemical fixation is a critical step in the analysis of the ultrastructure of seaweeds because the wrong approach can compromise the ability to distinguish fine-scale cellular composition. Fixation agents, fixation time and type of tissue are important factors to consider for transmission electron microscopy (TEM), and not every protocol is suitable for all cell types. We evaluated a range of fixation agents, post-fixation time and dehydration solutions to determine a TEM protocol for seaweeds in the Family Ulvaceae. We assessed Ulva lactuca using 5 protocols. The level of preservation obtained differed markedly between fixation methods The best result was obtained by fixing the sample with 2.5% glutaraldehyde, 0.05M sodium cacodylate buffer and 2% paraformaldehyde overnight, and 8h post-fixation in 1% in osmium tetroxide 1%. This approach and fixation time ensured that the membranes, especially the thylakoid membranes of chloroplasts, remained intact. Ethanol is recommended for dehydration as the use of acetone for dehydration resulted in the collapse of cellular membranes. This new protocol will ensure the ultrastructure of Ulvacean seaweeds can be clearly ascertained in the future., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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19. Morphological and ultrastructural characterization of the acidophilic and lipid-producer strain Chlamydomonas acidophila LAFIC-004 (Chlorophyta) under different culture conditions.
- Author
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Souza LD, Simioni C, Bouzon ZL, Schneider RC, Gressler P, Miotto MC, Rossi MJ, and Rörig LR
- Subjects
- Biodegradation, Environmental, Biofuels, Chlamydomonas growth & development, Coal Mining, Lipid Droplets metabolism, Microalgae classification, Microalgae metabolism, Microscopy, Electron, Transmission, Chlamydomonas metabolism, Chlamydomonas ultrastructure, Fatty Acids biosynthesis, Glucose metabolism, Heterotrophic Processes physiology, Phototrophic Processes physiology
- Abstract
Chlamydomonas acidophila LAFIC-004 is an acidophilic strain of green microalgae isolated from coal mining drainage. In the present work, this strain was cultivated in acidic medium (pH 3.6) under phototrophic, mixotrophic, and heterotrophic regimes to determine the best condition for growth and lipid production, simultaneously assessing possible morphological and ultrastructural alterations in the cells. For heterotrophic and mixotrophic treatments, two organic carbon sources were tested: 1 % glucose and 1 % sodium acetate. Lipid content and fatty acid profiles were only determined in phototrophic condition. The higher growth rates were achieved in phototrophic conditions, varying from 0.18 to 0.82 day
-1 . Glucose did not result in significant growth increase in either mixotrophic or heterotrophic conditions, and acetate proved to be toxic to the strain in both conditions. Oil content under phototrophic condition was 15.9 % at exponential growth phase and increased to 54.63 % at stationary phase. Based on cell morphology (flow cytometry and light microscopy) and ultrastructure (transmission electron microscopy), similar characteristics were observed between phototrophic and mixotrophic conditions with glucose evidencing many lipid bodies, starch granules, and intense fluorescence. Under the tested conditions, mixotrophic and heterotrophic modes did not result in increased neutral lipid fluorescence. It can be concluded that the strain is a promising lipid producer when grown until stationary phase in acidic medium and under a phototrophic regime, presenting a fatty acid profile suitable for biodiesel production. The ability to grow this strain in acidic mining residues suggests a potential for bioremediation with production of useful biomass.- Published
- 2017
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20. Erratum to: Toward establishing a morphological and ultrastructural characterization of proembryogenic masses and early somatic embryos of Araucaria angustifolia (Bert.) O. Kuntze.
- Author
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Steiner N, Farias-Soares FL, Schmidt ÉC, Pereira ML, Scheid B, Rogge-Renner GD, Bouzon ZL, Schmitz D, Maldonado S, and Guerra MP
- Published
- 2017
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21. The brown seaweed Sargassum cymosum: changes in metabolism and cellular organization after long-term exposure to cadmium.
- Author
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Costa GB, Simioni C, Pereira DT, Ramlov F, Maraschin M, Chow F, Horta PA, Bouzon ZL, and Schmidt ÉC
- Subjects
- Analysis of Variance, Antioxidants metabolism, Cadmium analysis, Carbohydrates analysis, Cell Survival drug effects, Chlorophyll metabolism, Chlorophyll A, Chromatography, High Pressure Liquid, Flavonoids analysis, Fluorescence, Multivariate Analysis, Phenols analysis, Photosynthesis drug effects, Principal Component Analysis, Sargassum drug effects, Sargassum ultrastructure, Seawater chemistry, Seaweed drug effects, Seaweed ultrastructure, Solubility, Cadmium toxicity, Sargassum cytology, Sargassum metabolism, Seaweed cytology, Seaweed metabolism
- Abstract
Sargassum cymosum was exposed to cadmium (Cd) to determine any physiological and ultrastructural effects. To accomplish this, S. cymosum samples were cultivated under photosynthetic active radiation (PAR) and Cd (0, 0.1, 0.2, 0.4 and 0.8 mg L
-1 ) during 7 and 14 days in laboratory-controlled conditions (0 mg L-1 Cd at both exposure times as control). Seaweeds had high retention capacity (over 90 %) for both exposure times. Growth rates showed significant increases by 14 days, especially for 0.1 and 0.4 mg L-1 Cd. Photosynthetic parameters were unaffected by Cd treatments. Chlorophyll contents were present in higher concentrations for all Cd treatments compared to respective control. Carotenoid profile showed significant differences in total composition and proportion of fucoxanthin and β-carotene, and no lutein was detected at 14 days. Phenolic and flavonoid compounds showed major accumulation at 14 days. Transmission electron microscopy (TEM) analyses presented major alterations in Cd-treated samples, when compared with respective control, in particular disorganization of cell wall fibrils. When compared to respective control samples, multivariate analyses showed disparate and complex interactions among metabolites in Cd-exposed seaweeds, giving evidence of physiological defence response. Thus, it can be concluded that Cd is a stressor for S. cymosum, resulting in physiological and structural alterations related to defence mechanisms against oxidative stress and toxicological effects resulting from long-term metal exposure. However, in the present paper, some observed changes also appear to result from acclimation mechanisms under lower concentration of Cd relative to the tolerance of S. cymosum to experimental conditions.- Published
- 2017
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22. Metabolomics of Ulva lactuca Linnaeus (Chlorophyta) exposed to oil fuels: Fourier transform infrared spectroscopy and multivariate analysis as tools for metabolic fingerprint.
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Pilatti FK, Ramlov F, Schmidt EC, Costa C, Oliveira ER, Bauer CM, Rocha M, Bouzon ZL, and Maraschin M
- Subjects
- Brazil, Gasoline analysis, Metabolomics, Models, Theoretical, Multivariate Analysis, Principal Component Analysis, Spectroscopy, Fourier Transform Infrared, Ulva metabolism, Environmental Monitoring methods, Fuel Oils analysis, Metabolome drug effects, Ulva drug effects
- Abstract
Fossil fuels, e.g. gasoline and diesel oil, account for substantial share of the pollution that affects marine ecosystems. Environmental metabolomics is an emerging field that may help unravel the effect of these xenobiotics on seaweeds and provide methodologies for biomonitoring coastal ecosystems. In the present study, FTIR and multivariate analysis were used to discriminate metabolic profiles of Ulva lactuca after in vitro exposure to diesel oil and gasoline, in combinations of concentrations (0.001%, 0.01%, 0.1%, and 1.0% - v/v) and times of exposure (30min, 1h, 12h, and 24h). PCA and HCA performed on entire mid-infrared spectral window were able to discriminate diesel oil-exposed thalli from the gasoline-exposed ones. HCA performed on spectral window related to the protein absorbance (1700-1500cm
-1 ) enabled the best discrimination between gasoline-exposed samples regarding the time of exposure, and between diesel oil-exposed samples according to the concentration. The results indicate that the combination of FTIR with multivariate analysis is a simple and efficient methodology for metabolic profiling with potential use for biomonitoring strategies., (Copyright © 2016 Elsevier Ltd. All rights reserved.)- Published
- 2017
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23. In vitro exposure of Ulva lactuca Linnaeus (Chlorophyta) to gasoline - Biochemical and morphological alterations.
- Author
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Pilatti FK, Ramlov F, Schmidt EC, Kreusch M, Pereira DT, Costa C, de Oliveira ER, Bauer CM, Rocha M, Bouzon ZL, and Maraschin M
- Subjects
- Biodegradation, Environmental, Carotenoids metabolism, Polyphenols metabolism, Seaweed metabolism, Seaweed ultrastructure, Starch metabolism, Ulva metabolism, Ulva ultrastructure, Gasoline toxicity, Seaweed drug effects, Ulva drug effects, Water Pollutants, Chemical toxicity
- Abstract
Refined fuels have considerable share of pollution of marine ecosystems. Gasoline is one of the most consumed fuel worldwide, but its effects on marine benthic primary producers are poorly investigated. In this study, Ulva lactuca was chosen as a biological model due to its cosmopolitan nature and tolerance to high levels and wide range of xenobiotics and our goal was to evaluate the effects of gasoline on ultrastructure and metabolism of that seaweed. The experimental design consisted of in vitro exposure of U. lactuca to four concentrations of gasoline (0.001%, 0.01%, 0.1%, and 1.0%, v/v) over 30 min, 1 h, 12 h, and 24 h, followed by cytochemical, SEM, and biochemical analysis. Increase in the number of cytoplasmic granules, loss of cell turgor, cytoplasmic shrinkage, and alterations in the mucilage were some of the ultrastructural alterations observed in thalli exposed to gasoline. Decrease in carotenoid and polyphenol contents, as well as increase of soluble sugars and starch contents were associated with the time of exposure to the xenobiotic. In combination, the results revealed important morphological and biochemical alterations in the phenotype of U. lactuca upon acute exposure to gasoline. This seaweed contain certain metabolites assigned as candidates to biomarkers of the environmental stress investigated and it is thought to be a promise species for usage in coastal ecosystems perturbation monitoring system. In addition, the findings suggest that U. lactuca is able to metabolize gasoline hydrocarbons and use them as energy source, acting as bioremediator of marine waters contaminated by petroleum derivatives., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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24. Synthesis, characterization and toxicological evaluation of Cr₂O₃ nanoparticles using Daphnia magna and Aliivibrio fischeri.
- Author
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Puerari RC, da Costa CH, Vicentini DS, Fuzinatto CF, Melegari SP, Schmidt ÉC, Bouzon ZL, and Matias WG
- Subjects
- Animals, Chromium Compounds chemistry, Daphnia growth & development, Daphnia physiology, Female, Metal Nanoparticles chemistry, Metal Nanoparticles ultrastructure, Microscopy, Electron, Transmission, Reproduction drug effects, Toxicity Tests, Acute, Toxicity Tests, Chronic, X-Ray Diffraction, Aliivibrio fischeri drug effects, Chromium Compounds toxicity, Daphnia drug effects, Metal Nanoparticles toxicity
- Abstract
Chromium III oxide (Cr2O3) nanoparticles (NPs) are used in pigments for ceramics, dyes, paints and cosmetics. However, few studies addressing the toxic potential of these NPs have been reported in the literature. Thus, this research aimed to evaluate the acute and chronic effects of Cr2O3 NPs through acute toxicity tests with Daphnia magna and Aliivibrio fischeri and chronic toxicity tests with Daphnia magna. Cr2O3 NPs were synthesized by the sol-gel method and characterized through TEM, X-Ray diffraction (XRD), zeta potential (ZP) and surface area analysis. In the acute toxicity tests the EC(50,48h) value obtained with D. magna was 6.79 mg L(-1) and for A. fischeri the EC(50,15min) value was 16.10 mg L(-1) and the EC(50,30min) value was 12.91 mg L(-1). Regarding the chronic toxicity tests with D. magna, effects on longevity (OEC=1.00 mg L(-1)), reproduction (OEC=1.00 mg L(-1)) and growth (OEC=0.50 mg L(-1)) were observed. On the SEM and TEM images, ultrastructural alterations in the organelles of exposed organisms were also observed. Thus, toxicological studies with NPs are of great importance in order to reduce the risk of environmental contamination., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2016
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25. Triterpene derivative: A potential signaling pathway for the fern-9(11)-ene-2α,3β-diol on insulin secretion in pancreatic islet.
- Author
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da Luz G, Frederico MJ, Castro AJ, Moraes AL, de Carvalho FK, Espíndola L, Schmidt ÉC, Bouzon ZL, Pizzolatti MG, and Silva FR
- Subjects
- Animals, Insulin Secretion, Male, Rats, Rats, Wistar, Insulin metabolism, Islets of Langerhans metabolism, Signal Transduction, Triterpenes pharmacology
- Abstract
Aim: Triterpenes and their derivatives influence on carbohydrate metabolism. In vivo and in vitro treatment investigated the effect of the natural triterpene fern-9(11)-ene-2α,3β-diol (1), isolated from Croton heterodoxus, and a derivative triterpene (2) on glucose homeostasis., Main Methods: The antidiabetic effect of the crude extract from C. heterodoxus leaves, the natural triterpene (1) as well as the derivative triterpene (2) were assayed on glucose tolerance. The effect and the mechanism of action on in vivo treatment with triterpene 2 on glycaemia and insulin secretion were studied. In addition, in vitro studies investigated the mechanism of triterpene 2 on glucose uptake and calcium influx on insulin secretion in pancreatic islets., Key Findings: The results show the extract slightly reduced the glycaemia when compared with hyperglycemic group. However, the presence of the substituent electron-withdrawing 4-nitrobenzoyl group in the A-ring of triterpene 2 powered the serum glucose lowering compared to triterpene 1. In addition, in vivo treatment with triterpene 2 significantly increased the insulin secretion induced by glucose and stimulated the glucose uptake and calcium influx in pancreatic islet. The effect of triterpene on calcium influx was completely inhibited by diazoxide, nifedipine and stearoylcarnitine treatment., Significance: The stimulatory effect of triterpene 2 on glucose uptake, calcium influx, regulation of potassium (K(+)-ATP) and calcium (L-VDCCs) channels activity as well as the pathway of PKC highlights the mechanism of action of the compound in pancreatic islets on insulin secretion and glucose homeostasis. In addition, this compound did not induce toxicity in this experimental condition., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2016
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26. The role of ascorbate peroxidase, guaiacol peroxidase, and polysaccharides in cassava (Manihot esculenta Crantz) roots under postharvest physiological deterioration.
- Author
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Uarrota VG, Moresco R, Schmidt EC, Bouzon ZL, Nunes Eda C, Neubert Ede O, Peruch LA, Rocha M, and Maraschin M
- Subjects
- Food Preservation, Food Storage, Manihot enzymology, Physiological Phenomena, Plant Roots chemistry, Plant Roots enzymology, Principal Component Analysis, Antioxidants analysis, Ascorbate Peroxidases analysis, Manihot chemistry, Manihot physiology, Peroxidase analysis, Starch analysis
- Abstract
This study aimed to investigate the role of ascorbate peroxidase (APX), guaiacol peroxidase (GPX), polysaccharides, and protein contents associated with the early events of postharvest physiological deterioration (PPD) in cassava roots. Increases in APX and GPX activity, as well as total protein contents occurred from 3 to 5 days of storage and were correlated with the delay of PPD. Cassava samples stained with Periodic Acid-Schiff (PAS) highlighted the presence of starch and cellulose. Degradation of starch granules during PPD was also detected. Slight metachromatic reaction with toluidine blue is indicative of increasing of acidic polysaccharides and may play an important role in PPD delay. Principal component analysis (PCA) classified samples according to their levels of enzymatic activity based on the decision tree model which showed GPX and total protein amounts to be correlated with PPD. The Oriental (ORI) cultivar was more susceptible to PPD., (Copyright © 2015 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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27. Seasonal biochemical and photophysiological responses in the intertidal macroalga Cystoseira tamariscifolia (Ochrophyta).
- Author
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Celis-Plá PS, Bouzon ZL, Hall-Spencer JM, Schmidt EC, Korbee N, and Figueroa FL
- Subjects
- Antioxidants analysis, Carbon analysis, Nitrogen analysis, Phaeophyceae chemistry, Phaeophyceae radiation effects, Phaeophyceae ultrastructure, Phenols analysis, Photosynthesis physiology, Seasons, Sunlight, Phaeophyceae physiology
- Abstract
Seasonal changes in the biochemistry and photophysiology of the brown macroalga Cystoseira tamariscifolia was analyzed in southern Spain. Total carbon and nitrogen contents, phenolic compounds, antioxidant and photosynthetic activities were seasonally determined over two years. Carbon, nitrogen and photoprotective phenolic contents were higher in winter and spring than in summer and autumn. Antioxidant levels were highest in spring and we found a positive correlation between phenolic content and antioxidant activity (EC50). Photosynthetic capacity (ETRmax) and photosynthetic efficiency (αETR) were also highest in spring, and there was a positive correlation between ETRmax and the amount of phenols present. Increased irradiance in spring enhanced algal productivity, antioxidant activity and the production of photoprotective compounds but in summer nutrient depletion due to thermal stratification of coastal waters reduced photosynthetic activity and the photoprotective capacity of C. tamariscifolia. Electron microscopy showed that phenols occurred in the cytoplasm of cortical cells inside physodes. Spring would be the best period to harvest C. tamariscifolia to extract photoprotectors and antioxidants for potential commercial uses, although the environmental impacts would need to be carefully assessed., (Copyright © 2015 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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28. Effects of UV-B radiation on germlings of the red macroalga Nemalion helminthoides (Rhodophyta).
- Author
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de Oliveira EM, Schmidt ÉC, Pereira DT, Bouzon ZL, and Ouriques LC
- Abstract
Studies have clearly demonstrated the damaging effects of UV-B exposure on macroalgae, but few have reported the impact of UV-B on spore germination and development at juvenile stages. Therefore, this work aimed to analyze the effects of UV-B radiation on germlings of Nemalion helminthoides at the tetrasporophytic phase. To accomplish this, germlings of N. helminthoides were cultivated in the laboratory and separated into two groups. The control group was exposed onlyto photosynthetic radiation, while the treatment group was exposed to photosynthetic radiation + UV-B for 2 hours during a period of 12 days. Control germlings showed increasing cellular proliferation and accumulation of reserve substances, as well as intense ramification in the last observed stages between 9 days and 12 days of development. Moreover, the chloroplasts presented a typical globular pyrenoid, profusely traversed by thylakoid membranes. Treated germlings, by contrast, showed intracellular damage, such as cell wall thickness, loss of chloroplast organization, changes in mitochondrial cristae, and increasing atrophy of the Golgi bodies. Additionally, changes in developmental patterns were observed, including loss of polarity in the first divisions of carpospores and abnormal stem ramification. The quantification of autofluorescence data coincided with the ultrastructural changes observed in the chloroplasts of cells exposed to UV-B. It can be concluded that exposure to radiation changed the developmental pattern and morphology of the germlings of N. helminthoides .
- Published
- 2016
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29. Toward establishing a morphological and ultrastructural characterization of proembryogenic masses and early somatic embryos of Araucaria angustifolia (Bert.) O. Kuntze.
- Author
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Steiner N, Farias-Soares FL, Schmidt ÉC, Pereira ML, Scheid B, Rogge-Renner GD, Bouzon ZL, Schmitz D, Maldonado S, and Guerra MP
- Subjects
- Culture Techniques, Seeds growth & development, Trees growth & development, Seeds ultrastructure, Trees ultrastructure
- Abstract
Somatic embryogenesis is a morphogenetic route useful for the study of embryonic development, as well as the large-scale propagation of endangered species, such as the Brazilian pine (Araucaria angustifolia). In the present study, we investigated the morphological and ultrastructural organization of A. angustifolia somatic embryo development by means of optical and electron microscopy. The proembryogenic stage was characterized by the proliferation of proembryogenic masses (PEMs), which are cellular aggregates composed of embryogenic cells (ECs) attached to suspensor-like cells (SCs). PEMs proliferate through three developmental stages, PEM I, II, and III, by changes in the number of ECs and SCs. PEM III-to-early somatic embryo (SE) transition was characterized by compact clusters of ECs growing out of PEM III, albeit still connected to it by SCs. Early SEs showed a dense globular embryonic mass (EM) and suspensor region (SR) connected by embryonic tube cells (TCs). By comparison, early somatic and zygotic embryos showed similar morphology. ECs are round with a large nucleus, nucleoli, and many cytoplasmic organelles. In contrast, TCs and SCs are elongated and vacuolated with cellular dismantling which is associated with programmed cell death of SCs. Abundant starch grains were observed in the TCs and SCs, while proteins were more abundant in the ECs. Based on the results of this study, a fate map of SE development in A. angustifolia is, for the first time, proposed. Additionally, this study shows the cell biology of SE development of this primitive gymnosperm which may be useful in evolutionary studies in this area.
- Published
- 2016
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30. Data supporting the role of enzymes and polysaccharides during cassava postharvest physiological deterioration.
- Author
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Uarrota VG, Moresco R, Schmidt EC, Bouzon ZL, da Costa Nunes E, de Oliveira Neubert E, Peruch LA, Rocha M, and Maraschin M
- Abstract
This data article is referred to the research article entitled The role of ascorbate peroxidase, guaiacol peroxidase, and polysaccharides in cassava (Manihot esculenta Crantz) roots under postharvest physiological deterioration by Uarrota et al. (2015). Food Chemistry 197, Part A, 737-746. The stress duo to PPD of cassava roots leads to the formation of ROS which are extremely harmful and accelerates cassava spoiling. To prevent or alleviate injuries from ROS, plants have evolved antioxidant systems that include non-enzymatic and enzymatic defence systems such as ascorbate peroxidase, guaiacol peroxidase and polysaccharides. In this data article can be found a dataset called "newdata", in RData format, with 60 observations and 06 variables. The first 02 variables (Samples and Cultivars) and the last 04, spectrophotometric data of ascorbate peroxidase, guaiacol peroxidase, tocopherol, total proteins and arcsined data of cassava PPD scoring. For further interpretation and analysis in R software, a report is also provided. Means of all variables and standard deviations are also provided in the Supplementary tables ("data.long3.RData, data.long4.RData and meansEnzymes.RData"), raw data of PPD scoring without transformation (PPDmeans.RData) and days of storage (days.RData) are also provided for data analysis reproducibility in R software.
- Published
- 2016
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31. Effects of copper and lead exposure on the ecophysiology of the brown seaweed Sargassum cymosum.
- Author
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Costa GB, de Felix MR, Simioni C, Ramlov F, Oliveira ER, Pereira DT, Maraschin M, Chow F, Horta PA, Lalau CM, da Costa CH, Matias WG, Bouzon ZL, and Schmidt ÉC
- Subjects
- Absorption, Physiological drug effects, Antioxidants metabolism, Chlorophyll metabolism, Chlorophyll A, Electron Transport drug effects, Fluorescence, Phenols metabolism, Photosynthesis drug effects, Seaweed growth & development, Seaweed ultrastructure, Water metabolism, Copper toxicity, Lead toxicity, Seaweed drug effects, Seaweed physiology
- Abstract
The effects of the heavy metals copper (Cu) and lead (Pb) on Sargassum cymosum were evaluated by determining uptake capacity, growth rates, photosynthetic efficiency, contents of photosynthetic pigments and phenolic compounds, 2,2-diphenyl-1-picrylhydrazyl radical-scavenging capacity, and morphological and cellular changes. S. cymosum was cultivated with Cu and Pb separately and combined at concentrations of 10, 25, and 50 μM for 7 days in laboratory-controlled conditions. Seaweeds under Cu treatment showed the highest biosorption capacity, and growth rates were significantly reduced compared to the control. The photosynthesis/irradiance curves showed alterations in kinetic patterns in the metal-treated samples. Specifically, Cu treatment alone inhibited electron transport rate (ETR) response, while Pb alone induced it. However, samples treated with both Cu and Pb (Cu + Pb) showed inhibition in ETR. The total amount of pigments increased relative to control. Light microscopy showed an increase in phenolic compounds, with physodes migrating towards cortical cells. Scanning electronic microscopy revealed alterations in the typical rough surface of thallus, when compared with control, especially for Pb treatments. Based on these results, it could be concluded that Cu and Pb are stress factors for S. cymosum, promoting alterations in seaweed metabolism and stimulating protective mechanisms against oxidative stress. However, the high bioaccumulation capacity of both heavy metals indicates a possible application for S. cymosum as a biosorbent agent for contaminated wastewater when metals are in low concentrations.
- Published
- 2016
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32. Histodifferentiation and ultrastructure of nodular cultures from seeds of Vriesea friburgensis Mez var. paludosa (L.B. Smith) L.B. Smith and leaf explants of Vriesea reitzii Leme & A. Costa (Bromeliaceae).
- Author
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Corredor-Prado JP, Schmidt EC, Guerra MP, Bouzon ZL, Dal Vesco LL, and Pescador R
- Abstract
Micropropagation via induction, multiplication and development of nodular cultures (NCs) is an efficient regeneration system for Bromeliaceae, a family of endangered monocot plants with ornamental value. Therefore, the present work aimed to induce NCs from seeds and leaf explants of Vriesea in order to characterize the morphological and histochemical aspects of induction and formation of these cultures. Seeds of Vriesea friburgensis var. paludosa were sterilized and inoculated into liquid culture media supplemented with different concentrations and combinations of growth regulators. Leaf explants of Vriesea reitzii were inoculated into medium supplemented with 4 μM α-naphthalene acetic acid (NAA) and 2 μM 6-benzylaminopurine (BAP). The addition of NAA (4 μM) in the culture medium used for seeds led to an induction rate of 72% in NCs. First, the embryo began to germinate, and afterwards, nodular structures started to form. While NCs formed from seeds is associated with root and shoot meristems, the formation of NCs from leaf explants involves the intercalary meristem. Meristematic cells generate an appropriate response in the induction medium, producing NCs by the proliferation of small cells with meristematic characteristics and large vacuolated cells. These results provide a better understanding of morphogenetic responses in bromeliads and, hence, the opportunity to develop optimized micropropagation protocols. Abbreviations : BAP, 6-benzylaminopurine; 2-iP, N6 (2-isopentyl) adenine; CBB, Coomassie Brilliant Blue; CLSM, confocal laser scanning microscopy; MSB, MS basal medium; NAA, α-Naphthalene acetic acid; NCs, nodular cultures; PAS, Periodic Acid-Schiff; SEM, scanning electron microscopy; TDZ, N-phenyl-N'-1,2,3-thidiazol-5-ylurea; TB-O, Toluidine Blue O; TEM, Transmission electron microscopy.
- Published
- 2015
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33. The effect of different concentrations of copper and lead on the morphology and physiology of Hypnea musciformis cultivated in vitro: a comparative analysis.
- Author
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Santos RW, Schmidt ÉC, Vieira IC, Costa GB, Rover T, Simioni C, Barufi JB, Soares CH, and Bouzon ZL
- Subjects
- Chlorophyll metabolism, Copper metabolism, Flavonoids metabolism, Lead metabolism, Phenols metabolism, Photosynthesis, Phycocyanin metabolism, Plant Proteins metabolism, Rhodophyta drug effects, Rhodophyta ultrastructure, Seawater chemistry, Water Pollutants, Chemical metabolism, Copper toxicity, Lead toxicity, Rhodophyta growth & development, Water Pollutants, Chemical toxicity
- Abstract
Copper and lead, as remnants of industrial activities and urban effluents, have heavily contaminated many aquatic environments. Therefore, this study aimed to determine their effects on the physiological, biochemical, and cell organization responses of Hypnea musciformis under laboratory conditions during a 7-day experimental period. To accomplish this, segments of H. musciformis were exposed to photosynthetic active radiation at 80 μmol photons m(-2) s(-1), Cu (0.05 and 0.1 mg kg(-1)), and Pb (3.5 and 7 mg kg(-1)). Various intracellular abnormalities resulted from exposure to Cu and Pb, including a decrease in phycobiliproteins. Moreover, carotenoid and flavonoid contents, as well as phenolic compounds, were decreased, an apparent reflection of chemical antioxidant defense against reactive oxygen species. Treatment with Cu and Pb also caused an increase in the number of floridean starch grains, probably as a defense against nutrient deprivation. Compared to plants treated with lead, those treated with copper showed higher metabolic and ultrastructural alterations. These results suggest that H. musciformis more readily internalizes copper through transcellular absorption. Finally, as a result of ultrastructural damage and metabolic changes observed in plants exposed to different concentrations of Cu and Pb, a significant reduction in growth rates was observed. Nevertheless, the results indicated different susceptibility of H. musciformis to different concentrations of Cu and Pb.
- Published
- 2015
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34. Cephalothrix gen. nov. (Cyanobacteria): towards an intraspecific phylogenetic evaluation by multilocus analyses.
- Author
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da Silva Malone CF, Rigonato J, Laughinghouse HD, Schmidt ÉC, Bouzon ZL, Wilmotte A, Fiore MF, and Sant'Anna CL
- Subjects
- Cyanobacteria cytology, Cyanobacteria ultrastructure, DNA, Bacterial genetics, DNA, Ribosomal Spacer genetics, Microscopy, Electron, Transmission, Molecular Sequence Data, Phylogeny, RNA, Ribosomal, 16S genetics, Sequence Analysis, DNA, Cyanobacteria classification
- Abstract
For more than a decade, the taxonomy of the Phormidiaceae has been problematic, since morphologically similar organisms represent phylogenetically distinct entities. Based on 16S rRNA gene sequence analyses, the polyphyletic genus Phormidium and other gas-vacuolated oscillatorioids appear scattered throughout the cyanobacterial tree of life. Recently, several studies have focused on understanding the oscillatorioid taxa at the generic level. At the specific level, few studies have characterized cyanobacterial strains using combined datasets (morphology, ultrastructure and molecular multilocus analyses). Using a multifaceted approach, we propose a new, well-defined genus, Cephalothrix gen. nov., by analysing seven filamentous strains that are morphologically 'intermediate' between gas-vacuolated taxa and Phormidium. Furthermore, we characterize two novel species: Cephalothrix komarekiana sp. nov. (strains CCIBt 3277, CCIBt 3279, CCIBt 3523, CCALA 155, SAG 75.79 and UTEX 1580) and Cephalothrix lacustris sp. nov. (strain CCIBt 3261). The generic name and specific epithets are proposed under the provisions of the International Code of Nomenclature for Algae, Fungi, and Plants.
- Published
- 2015
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35. Effects of cadmium metal on young gametophytes of Gelidium floridanum: metabolic and morphological changes.
- Author
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Simioni C, Schmidt ÉC, Rover T, dos Santos R, Filipin EP, Pereira DT, Costa GB, Oliveira ER, Chow F, Ramlov F, Ouriques L, Maraschin M, and Bouzon ZL
- Subjects
- Carotenoids metabolism, Chlorophyll metabolism, Chloroplasts metabolism, Electron Transport, Germ Cells, Plant physiology, Germ Cells, Plant ultrastructure, Photosynthesis, Rhodophyta cytology, Rhodophyta physiology, Cadmium toxicity, Germ Cells, Plant drug effects, Rhodophyta drug effects, Water Pollutants, Chemical toxicity
- Abstract
By evaluating carotenoid content, photosynthetic pigments and changes in cellular morphology, growth rates, and photosynthetic performance, this study aimed to determine the effect of cadmium (Cd) on the development of young gametophytes of Gelidium floridanum. Plants were exposed to 7.5 and 15 μM of Cd for 7 days. Control plants showed increased formation of new filamentous thallus, increased growth rates, presence of starch grains in the cortical and subcortical cells, protein content distributed regularly throughout the cell periphery, and intense autofluorescence of chloroplasts. On the other hand, plants treated with Cd at concentrations of 7.5 and 15 μM showed few formations of new thallus with totally depigmented regions, resulting in decreased growth rates. Plants exposed to 7.5 μM Cd demonstrated alterations in the cell wall and an increase in starch grains in the cortical and subcortical cells, while plants exposed to 15 μM Cd showed changes in medullary cells with no organized distribution of protein content. The autofluorescence and structure of chloroplasts decreased, forming a thin layer on the periphery of cells. Cadmium also affected plant metabolism, as visualized by a decrease in photosynthetic pigments, in particular, phycoerythrin and phycocyanin contents, and an increase in carotenoids. This result agrees with decreased photosynthetic performance and chronic photoinhibition observed after treatment with Cd, as measured by the decrease in electron transport rate. Based on these results, it was concluded that exposure to Cd affects cell metabolism and results in significant toxicity to young gametophytes of G. floridanum.
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- 2015
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36. Effects of eutrophic seawater and temperature on the physiology and morphology of Hypnea musciformis J. V. Lamouroux (Gigartinales, Rhodophyta).
- Author
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de Faveri C, Schmidt ÉC, Simioni C, Martins CD, Bonomi-Barufi J, Horta PA, and Bouzon ZL
- Subjects
- Biomass, Rhodophyta cytology, Rhodophyta growth & development, Seawater, Temperature, Water Purification, Photosynthesis physiology, Rhodophyta physiology, Sewage adverse effects, Water Pollutants toxicity
- Abstract
As both food and source of a kappa-carrageenan, Hypnea musciformis represents a species of great economic interest. It also synthesizes substances with antiviral, anti-helminthic and anti-inflammatory potential and shows promise for use as a bioindicator of cadmium. In this study, we investigated the combined effects of seawater from three urbanized areas (area 1: natural runoff, NRA; area 2: urbanized runoff and sewage with treatment, RTA; area 3: urbanized runoff and untreated sewage, RUS) and three different temperatures (15, 25 and 30 °C) on the growth rate, photosynthetic efficiency, photosynthetic pigments and cell morphology of H. musciformis. After 4 days (96 h) of culture, the biomass of H. musciformis showed differences that fluctuated among the areas and temperature treatments. Specifically, the specimens cultivated in 35 °C had low values of ETRmax, α(ETR), β(ETR), and Fv/Fm photosynthetic parameters, as well as changes in cell morphology, with reduction in photosynthetic pigments and drastic reduction in growth rates. When combined with the extreme temperatures, high concentrations of ammonium ion in seawater effluent caused an inhibition of photosynthetic activity, as well as significant variation in chlorophyll a and carotenoid contents. As observed by light microscopy, the synergism between different temperatures and pollutants found in eutrophic waters caused changes in cellular morphology with increased cell wall thickening and decreased floridean starch grains. H. musciformis also showed important changes in physiological response to each factor independently, as well as changes resulting from the synergistic interaction of these factors combined. Therefore, we can conclude that extreme temperature combined with the effect of eutrophic waters, especially RUS, caused distinct morphological and physiological changes in the red alga H. musciformis.
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- 2015
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37. Effects of ultraviolet radiation (UVA+UVB) and copper on the morphology, ultrastructural organization and physiological responses of the red alga Pterocladiella capillacea.
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Schmidt ÉC, Kreusch M, Felix MR, Pereira DT, Costa GB, Simioni C, Ouriques LC, Farias-Soares FL, Steiner N, Chow F, Ramlov F, Maraschin M, and Bouzon ZL
- Subjects
- Cell Wall drug effects, Cell Wall ultrastructure, Chlorophyll biosynthesis, Chlorophyll A, Chloroplasts drug effects, Chloroplasts physiology, Chloroplasts ultrastructure, Microscopy, Electron, Transmission, Photoperiod, Photosynthesis drug effects, Photosynthesis physiology, Phycobiliproteins biosynthesis, Pigments, Biological biosynthesis, Rhodophyta drug effects, Rhodophyta physiology, Rhodophyta ultrastructure, Ultraviolet Rays, Cell Wall radiation effects, Chloroplasts radiation effects, Copper toxicity, Photons, Photosynthesis radiation effects, Rhodophyta radiation effects
- Abstract
The effect of ultraviolet (UV) radiation and copper (Cu) on apical segments of Pterocladiella capillacea was examined under two different conditions of radiation, PAR (control) and PAR+UVA+UVB (PAR+UVAB), and three copper concentrations, ranging from 0 (control) to 0.62, 1.25 and 2.50 μm. Algae were exposed in vitro to photosynthetically active radiation (PAR) at 70 μmol photons m(-2) s(-1) , PAR + UVB at 0.35 W m(-2) and PAR +UVA at 0.70 W m(-2) during a 12-h photocycle for 3 h each day for 7 days. The effects of radiation and copper on growth rates, content of photosynthetic pigments and photosynthetic performance were analyzed. In addition, samples were processed for light and transmission electron microscopy. The content of photosynthetic pigments decreased after exposure to radiation and Cu. Compared with PAR radiation and copper treatments modified the kinetics patterns of the photosynthesis/irradiance curve. The treatments also caused changes in the ultrastructure of cortical and subcortical cells, including increased cell wall thickness and accumulation of plastoglobuli, as well as changes in the organization of chloroplasts. The results indicate that the synergistic interaction between UV radiation and Cu in P. capillacea, led to the failure of protective mechanisms and causing more drastic changes and cellular imbalances., (© 2014 The American Society of Photobiology.)
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- 2015
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38. Ultrastructural and structural characterization of zygotes and embryos during development in Sargassum cymosum (Phaeophyceae, Fucales).
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Rover T, Simioni C, Hable W, and Bouzon ZL
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- Microscopy, Confocal, Microscopy, Electron, Transmission, Sargassum growth & development, Zygote ultrastructure, Sargassum ultrastructure
- Abstract
This study investigates the pattern and performance of cellular structures during the early development of zygotes and embryos of Sargassum cymosum. The early development S. cymosum germlings has already been characterized and compared with the pattern of development established for all fucoid algae, in which the zygote remains attached to the receptacle by mucilage during the establishment of polarity and early cell division. As in the algae Fucus and Silvetia, the first division is transverse across the longer axis of the zygote of S. cymosum. However, the cell that will give rise to the rhizoids is not determined in the first division; rather, the formation of this cell occurs with the second division, forming a small cell in the embryo shaded site. Stabilizing polarity during the process of forming a multicellular embryo occurs rapidly. During development, significant cytoplasmic alterations take place. Initially, the cytoplasm shows large clusters of phenolic compounds located in specific parts, but later, in the course of development, these compounds are dispersed in the cytoplasm, although a significant amount remains confined to the nucleus. Moreover, to produce more zygotes and higher growth rates for the germlings, the best conditions found for the species S. cymosum were 22 and 26 °C, respectively.
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- 2015
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39. The mechanism of action of ursolic acid as insulin secretagogue and insulinomimetic is mediated by cross-talk between calcium and kinases to regulate glucose balance.
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Castro AJ, Frederico MJ, Cazarolli LH, Mendes CP, Bretanha LC, Schmidt ÉC, Bouzon ZL, de Medeiros Pinto VA, da Fonte Ramos C, Pizzolatti MG, and Silva FR
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- Animals, Calcium blood, Cell Membrane drug effects, Cell Membrane metabolism, Dose-Response Relationship, Drug, Gene Expression drug effects, Glucose metabolism, Glucose Transporter Type 4 genetics, Glucose Transporter Type 4 metabolism, Glycogen metabolism, Hypoglycemic Agents pharmacology, Immunoblotting, Insulin blood, Insulin pharmacology, Insulin Secretion, Insulin-Secreting Cells drug effects, Insulin-Secreting Cells metabolism, Insulin-Secreting Cells ultrastructure, L-Lactate Dehydrogenase blood, L-Lactate Dehydrogenase metabolism, Male, Microscopy, Electron, Transmission, Molecular Structure, Muscle, Skeletal drug effects, Muscle, Skeletal metabolism, Rats, Wistar, Reverse Transcriptase Polymerase Chain Reaction, Triterpenes chemistry, Ursolic Acid, Blood Glucose metabolism, Calcium metabolism, Insulin metabolism, Protein Kinases metabolism, Triterpenes pharmacology
- Abstract
Background: The effect of in vivo treatment with ursolic acid (UA) on glycemia in hyperglycemic rats and its mechanism of action on muscle were studied., Methods: The UA effects on glycemia, glycogen, LDH, calcium and on insulin levels were evaluated after glucose tolerance curve. The β-cells were evaluated through the transmission electron microscopy. UA mechanism of action was studied on muscles through the glucose uptake with/without specific insulin signaling inhibitors. The nuclear effect of UA and the GLUT4 expression on muscle were studied using thymidine, GLUT4 immunocontent, immunofluorescence and RT-PCR., Results: UA presented a potent antihyperglycemic effect, increased insulin vesicle translocation, insulin secretion and augmented glycogen content. Also, UA stimulates the glucose uptake through the involvement of the classical insulin signaling related to the GLUT4 translocation to the plasma membrane as well as the GLUT4 synthesis. These were characterized by increasing the GLUT4 mRNA expression, the activation of DNA transcription, the expression of GLUT4 and its presence at plasma membrane. Also, the modulation of calcium, phospholipase C, protein kinase C and PKCaM II is mandatory for the full stimulatory effect of UA on glucose uptake. UA did not change the serum LDH and serum calcium balance., Conclusions: The antihyperglycemic role of UA is mediated through insulin secretion and insulinomimetic effect on glucose uptake, synthesis and translocation of GLUT4 by a mechanism of cross-talk between calcium and protein kinases., General Significance: UA is a potential anti-diabetic agent with pharmacological properties for insulin resistance and diabetes therapy., (Copyright © 2014 Elsevier B.V. All rights reserved.)
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- 2015
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40. Toxicological effects of copper oxide nanoparticles on the growth rate, photosynthetic pigment content, and cell morphology of the duckweed Landoltia punctata.
- Author
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Lalau CM, Mohedano Rde A, Schmidt ÉC, Bouzon ZL, Ouriques LC, dos Santos RW, da Costa CH, Vicentini DS, and Matias WG
- Subjects
- Nanoparticles, Araceae chemistry, Copper chemistry, Photosynthesis physiology
- Abstract
Recently, the application of copper oxide nanoparticles (CuO-NPs) has increased considerably, primarily in scientific and industrial fields. However, studies to assess their health risks and environmental impacts are scarce. Therefore, the present study aims to evaluate the toxicological effects of CuO-NPs on the duckweed species Landoltia punctata, which was used as a test organism. To accomplish this, duckweed was grown under standard procedures according to ISO DIS 20079 and exposed to three different concentrations of CuO-NPs (0.1, 1.0, and 10.0 g L(-1)), with one control group (without CuO-NPs). The toxicological effects were measured based on growth rate inhibition, changes in the plant's morphology, effects on ultrastructure, and alterations in photosynthetic pigments. The morphological and ultrastructural effects were evaluated by electronic, scanning and light microscopic analysis, and CuO-NPs were characterized using transmission electron microscopy (TEM), zeta potential, and superficial area methods of analysis. This analysis was performed to evaluate nanoparticle size and form in solution and sample stability. The results showed that CuO-NPs affected morphology more significantly than growth rate. L. punctata also showed the ability to remove copper ions. However, for this plant to be representative within the trophic chain, the biomagnification of effects must be assessed.
- Published
- 2015
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41. The effect of cadmium under different salinity conditions on the cellular architecture and metabolism in the red alga Pterocladiella capillacea (Rhodophyta, Gelidiales).
- Author
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de L Felix MR, Osorio LK, Ouriques LC, Farias-Soares FL, Steiner N, Kreusch M, Pereira DT, Simioni C, Costa GB, Horta PA, Chow F, Ramlov F, Maraschin M, Bouzon ZL, and Schmidt EC
- Subjects
- Metabolome, Microscopy, Pigments, Biological analysis, Rhodophyta chemistry, Rhodophyta cytology, Salinity, Spectrum Analysis, Cadmium toxicity, Rhodophyta drug effects, Rhodophyta growth & development
- Abstract
The in vitro effect of cadmium (Cd) on apical segments of Pterocladiella capillacea was examined. Over a period of 7 days, the segments were cultivated with the combination of different salinities (25, 35, and 45 practical salinity units) and Cd concentrations, ranging from 0.17 to 0.70 ppm. The effects of Cd on growth rates and content of photosynthetic pigments were analyzed. In addition, metabolic profiling was performed, and samples were processed for microscopy. Serious damage to physiological performance and ultrastructure was observed under different combinations of Cd concentrations and salinity values. Elementary infrared spectroscopy revealed toxic effects registered on growth rate, photosynthetic pigments, chloroplast, and mitochondria organization, as well as changes in lipids and carbohydrates. These alterations in physiology and ultrastructure were, however, coupled to activation of such defense mechanisms as cell wall thickness, reduction of photosynthetic harvesting complex, and flavonoid. In conclusion, P. capillacea is especially sensitive to Cd stress when intermediate concentrations of this pollutant are associated with low salinity values. Such conditions resulted in metabolic compromise, reduction of primary productivity, i.e., photosynthesis, and carbohydrate accumulation in the form of starch granules. Taken together, these findings improve our understanding of the potential impact of this metal in the natural environment.
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- 2014
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42. Effects of ultraviolet radiation (UVA+UVB) on young gametophytes of Gelidium floridanum: growth rate, photosynthetic pigments, carotenoids, photosynthetic performance, and ultrastructure.
- Author
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Simioni C, Schmidt EC, Felix MR, Polo LK, Rover T, Kreusch M, Pereira DT, Chow F, Ramlov F, Maraschin M, and Bouzon ZL
- Subjects
- Carotenoids biosynthesis, Cell Wall radiation effects, Cell Wall ultrastructure, Chlorophyll biosynthesis, Electron Transport radiation effects, Gametogenesis, Plant physiology, Microscopy, Electron, Photosynthesis physiology, Phycocyanin antagonists & inhibitors, Phycocyanin biosynthesis, Phycoerythrin antagonists & inhibitors, Phycoerythrin biosynthesis, Rhodophyta growth & development, Rhodophyta metabolism, Rhodophyta ultrastructure, Ultraviolet Rays, Electrons, Gametogenesis, Plant radiation effects, Photosynthesis radiation effects, Rhodophyta radiation effects
- Abstract
This study investigated the effects of radiation (PAR+UVA+UVB) on the development and growth rates (GRs) of young gametophytes of Gelidium floridanum. In addition, photosynthetic pigments were quantified, carotenoids identified, and photosynthetic performance assessed. Over a period of 3 days, young gametophytes were cultivated under laboratory conditions and exposed to photosynthetically active radiation (PAR) at 80 μmol photons m(-2) s(-1) and PAR+UVA (0.70 W m(-2))+UVB (0.35 W m(-2)) for 3 h per day. The samples were processed for light and electron microscopy to analyze the ultrastructure features, as well as carry out metabolic studies of GRs, quantify the content of photosynthetic pigments, identify carotenoids and assess photosynthetic performance. PAR+UVA+UVB promoted increase in cell wall thickness, accumulation of floridean starch grains in the cytoplasm and disruption of chloroplast internal organization. Algae exposed to PAR+UVA+UVB also showed a reduction in GR of 97%. Photosynthetic pigments, in particular, phycoerythrin and allophycocyanin contents, decreased significantly from UV radiation exposure. This result agrees with the decrease in photosynthetic performance observed after exposure to ultraviolet radiation, as measured by a decrease in the electron transport rate (ETR), where values of ETRmax declined approximately 44.71%. It can be concluded that radiation is a factor that affects the young gametophytes of G. floridanum at this stage of development., (© 2014 The American Society of Photobiology.)
- Published
- 2014
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43. Gills are an initial target of zinc oxide nanoparticles in oysters Crassostrea gigas, leading to mitochondrial disruption and oxidative stress.
- Author
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Trevisan R, Delapedra G, Mello DF, Arl M, Schmidt ÉC, Meder F, Monopoli M, Cargnin-Ferreira E, Bouzon ZL, Fisher AS, Sheehan D, and Dafre AL
- Subjects
- Animals, Gills drug effects, Gills ultrastructure, Hemocytes drug effects, Lethal Dose 50, Lipid Peroxidation drug effects, Microscopy, Electron, Transmission, Mitochondria drug effects, Crassostrea drug effects, Nanoparticles toxicity, Oxidative Stress drug effects, Water Pollutants, Chemical toxicity, Zinc Oxide toxicity
- Abstract
The increasing industrial use of nanomaterials during the last decades poses a potential threat to the environment and in particular to organisms living in the aquatic environment. In the present study, the toxicity of zinc oxide nanoparticles (ZnONP) was investigated in Pacific oysters Crassostrea gigas. The nanoscale of ZnONP, in vehicle or ultrapure water, was confirmed, presenting an average size ranging from 28 to 88 nm. In seawater, aggregation was detected by TEM and DLS analysis, with an increased average size ranging from 1 to 2 μm. Soluble or nanoparticulated zinc presented similar toxicity, displaying a LC50 (96 h) around 30 mg/L. High zinc dissociation from ZnONP, releasing ionic zinc in seawater, is a potential route for zinc assimilation and ZnONP toxicity. To investigate mechanisms of toxicity, oysters were treated with 4 mg/L ZnONP for 6, 24 or 48 h. ZnONP accumulated in gills (24 and 48 h) and digestive glands (48 h). Ultrastructural analysis of gills revealed electron-dense vesicles near the cell membrane and loss of mitochondrial cristae (6 h). Swollen mitochondria and a more conspicuous loss of mitochondrial cristae were observed after 24 h. Mitochondria with disrupted membranes and an increased number of cytosolic vesicles displaying electron-dense material were observed 48 h post exposure. Digestive gland showed similar changes, but these were delayed relative to gills. ZnONP exposure did not greatly affect thiol homeostasis (reduced and oxidized glutathione) or immunological parameters (phagocytosis, hemocyte viability and activation and total hemocyte count). At 24 h post exposure, decreased (-29%) glutathione reductase (GR) activity was observed in gills, but other biochemical responses were observed only after 48 h of exposure: lower GR activity (-28%) and levels of protein thiols (-21%), increased index of lipid peroxidation (+49%) and GPx activity (+26%). In accordance with ultrastructural changes and zinc load, digestive gland showed delayed biochemical responses. Except for a decreased GR activity (-47%) at 48 h post exposure, the biochemical alterations seen in gills were not present in digestive gland. The results indicate that gills are able to incorporate zinc prior (24 h) to digestive gland (48 h), leading to earlier mitochondrial disruption and oxidative stress. Our data suggest that gills are the initial target of ZnONP and that mitochondria are organelles particularly susceptible to ZnONP in C. gigas., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
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44. Bioabsorption of cadmium, copper and lead by the red macroalga Gelidium floridanum: physiological responses and ultrastructure features.
- Author
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dos Santos RW, Schmidt ÉC, de L Felix MR, Polo LK, Kreusch M, Pereira DT, Costa GB, Simioni C, Chow F, Ramlov F, Maraschin M, and Bouzon ZL
- Subjects
- Cell Respiration drug effects, Microscopy, Electron, Scanning, Microscopy, Electron, Transmission, Photosynthesis drug effects, Pigments, Biological metabolism, Rhodophyta growth & development, Rhodophyta ultrastructure, Metals, Heavy metabolism, Metals, Heavy toxicity, Rhodophyta drug effects, Rhodophyta metabolism, Water Pollutants, Chemical metabolism, Water Pollutants, Chemical toxicity
- Abstract
Heavy metals, such as lead, copper, cadmium, zinc, and nickel, are among the most common pollutants found in both industrial and urban effluents. High concentrations of these metals cause severe toxic effects, especially to organisms living in the aquatic ecosystem. Cadmium (Cd), lead (Pb) and copper (Cu) are the heavy metals most frequently implicated as environmental contaminants, and they have been shown to affect development, growth, photosynthesis and respiration, and morphological cell organization in seaweeds. This paper aimed to evaluate the effects of 50μM and 100μM of Cd, Pb and Cu on growth rates, photosynthetic pigments, biochemical parameters and ultrastructure in Gelidium floridanum. To accomplish this, apical segments of G. floridanum were individually exposed to the respective heavy metals over a period of 7 days. Plants exposed to Cd, Cu and Pb showed discoloration of thallus pigmentation, chloroplast alteration, especially degeneration of thylakoids, and decrease in photosynthetic pigments, such as chlorophyll a and phycobiliproteins, in samples treated with Cd and Cu. Moreover, cell wall thickness and the volume of plastoglobuli increased. X-ray microanalysis detected Cd, Cu and Pb absorption in the cell wall. The results indicate that Cd, Pb and Cu negatively affect metabolic performance and cell ultrastructure in G. floridanum and that Cu was more toxic than either Pb or Cd., (Copyright © 2014 Elsevier Inc. All rights reserved.)
- Published
- 2014
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45. Effects of brefeldin A on the endomembrane system and germ tube formation of the tetraspore of Gelidium floridanum (Rhodophyta, Florideophyceae).
- Author
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Simioni C, Rover T, Schmidt ÉC, de L Felix MR, Polo LK, Santos RD, Costa GB, Kreusch M, Pereira DT, Ouriques LC, and Bouzon ZL
- Abstract
Gelidium floridanum W.R. Taylor tetraspores are units of dispersal and are responsible for substrate attachment. This study aimed to examine evidence of direct interaction between germ tube formation and Golgi activity during tetraspore germination of G. floridanum. After release, the tetraspores were incubated with brefeldin A (BFA) in concentrations of 4 and 8 μM over a 6 h period. The controls and treatments were analyzed with light, fluorescence (FM4-64 dye) and transmission electron microscopy. In the control samples, the Golgi bodies were responsible for germ tube formation. In contrast, BFA-treated samples were observed to inhibit spore adhesion and germ tube formation. These tetraspores also showed an increase in volume (≥30 μm width). BFA treatment also resulted in the disassembly of Golgi cisternae and the formation of vesiculated areas of the cytoplasm, blocking the secretion of protein and amorphous matrix polysaccharides. When stained with FM4-64, the control samples showed fluorescence in the apical region of the germ tube, but the treated samples showed an intense fluorescence throughout the cytoplasm. From these results, we can conclude that the germ tube is formed by the incorporation of vesicles derived from Golgi. Thus, vesicle secretion and Golgi organization are basic processes and essential in adhesion and tube formation. By blocking the secretion of protein and amorphous matrix polysaccharides, BFA treatment precluded tetraspore germination., (© 2014 Phycological Society of America.)
- Published
- 2014
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46. Photoacclimation responses of the brown macroalga Sargassum Cymosum to the combined influence of UV radiation and salinity: cytochemical and ultrastructural organization and photosynthetic performance.
- Author
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Polo LK, Felix MR, Kreusch M, Pereira DT, Costa GB, Simioni C, Ouriques LC, Chow F, Ramlov F, Maraschin M, Bouzon ZL, and Schmidt EC
- Subjects
- Electron Transport, Marine Biology, Microscopy, Electron, Transmission, Phaeophyceae radiation effects, Phaeophyceae ultrastructure, Pigments, Biological metabolism, Adaptation, Physiological, Phaeophyceae physiology, Photosynthesis, Salinity, Ultraviolet Rays
- Abstract
The photoacclimation responses of the brown macroalga Sargassum cymosum were studied to determine its cytochemical and ultrastructural organization, as well as photosynthetic pigments and performance. S. cymosum was cultivated in three salinities (30, 35 and 40 psu) under four irradiation treatments: PAR-only, PAR + UVA, PAR + UVB and PAR + UVA + UVB. Plants were exposed to PAR at 70 μmol photons m(-2) s(-1), PAR + UVB at 0.35 W m(-2) and PAR +UVA at 0.70 W m(-2) for 3 h per day during 7 days in vitro. Growth rate was not significantly affected by any type of radiation or salinity. The amount of pigments in S. cymosum was significantly influenced by the interaction of salinity and radiation treatments. Compared with PAR-only, UVR treatments modified the kinetics patterns of the photosynthesis/irradiance curve. After exposure to UVR, S. cymosum increased cell wall thickness and the presence of phenolic compounds. The number of mitochondria increased, whereas the number of chloroplasts showed few changes. Although S. cymosum showed insensitivity to changes in salinity, it can be concluded that samples treated under four irradiation regimes showed structural changes, which were more evident, but not severe, under PAR + UVB treatment., (© 2013 The American Society of Photobiology.)
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- 2014
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47. Effect of ultraviolet-B radiation in laboratory on morphological and ultrastructural characteristics and physiological parameters of selected cultivar of Oryza sativa L.
- Author
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de Almeida SL, Schmidt ÉC, Pereira DT, Kreusch M, Felix MR, Osorio LK, de Paula Martins R, Latini A, Ramlov F, Chow F, Maraschin M, Rodrigues AC, and Bouzon ZL
- Subjects
- Oryza radiation effects, Photosynthesis radiation effects, Pigments, Biological metabolism, Plant Epidermis cytology, Plant Epidermis radiation effects, Plant Epidermis ultrastructure, Plant Leaves anatomy & histology, Plant Leaves radiation effects, Plant Proteins metabolism, Polyphenols metabolism, Solubility, Oryza physiology, Oryza ultrastructure, Ultraviolet Rays
- Abstract
Ultraviolet-B radiation (UVBR) affects plants in many important ways, including reduction of growth rate and primary productivity, and changes in ultrastructures. Rice (Oryza sativa) is one of the most cultivated cereals in the world, along with corn and wheat, representing over 50% of agricultural production. In this study, we examined O. sativa plants exposed to ambient outdoor radiation and laboratory-controlled photosynthetically active radiation (PAR) and PAR + UVBR conditions for 2 h/day during 30 days of cultivation. The samples were studied for morphological and ultrastructural characteristics, and physiological parameters. PAR + UVBR caused changes in the ultrastructure of leaf of O. sativa and leaf morphology (leaf index, leaf area and specific leaf area, trichomes, and papillae), plant biomass (dry and fresh weight), photosynthetic pigments, phenolic compounds, and protein content. As a photoprotective acclimation strategy against PAR + UVBR damage, an increase of 66.24% in phenolic compounds was observed. Furthermore, PAR + UVBR treatment altering the levels of chlorophylls a and b, and total chlorophyll. In addition, total carotenoid contents decreased after PAR + UVBR treatment. The results strongly suggested that PAR + UVBR negatively affects the ultrastructure, morphology, photosynthetic pigments, and growth rates of leaf of O. sativa and, in the long term, it could affect the viability of this economically important plant.
- Published
- 2013
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48. Virus, protozoa and organic compounds decay in depurated oysters.
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Souza DS, Piazza RS, Pilotto MR, do Nascimento Mde A, Moresco V, Taniguchi S, Leal DA, Schmidt Éd, Cargin-Ferreira E, Bícego MC, Sasaki ST, Montone RC, de Araujo RA, Franco RM, Bouzon ZL, Bainy AC, and Barardi CR
- Subjects
- Animals, Digestive System radiation effects, Food Contamination prevention & control, Gills radiation effects, Organic Chemicals analysis, Virus Physiological Phenomena radiation effects, Water Pollutants, Chemical analysis, Water Pollutants, Chemical chemistry, Water Pollutants, Chemical radiation effects, Cryptosporidium radiation effects, Giardia radiation effects, Organic Chemicals radiation effects, Ostreidae chemistry, Ostreidae parasitology, Ostreidae radiation effects, Ostreidae virology, Ultraviolet Rays, Viruses radiation effects
- Abstract
Aims: (1) Evaluate the dynamic of the depuration process of Crassostrea gigas oysters using different ultraviolet doses with different amounts of contaminants (virus, protozoa and organic contaminants) and (2) investigate the morphological changes in the oysters' tissues produced by the depuration procedures., Methods: The oysters were allocated in sites with different degrees of contamination and analyzed after 14 days. Some animals were used as positive controls by artificial bioaccumulation with HAdV2 and MNV1 and subjected to depuration assays using UV lamps (18 or 36 W) for 168 h. The following pollutants were researched in the naturally contaminated oysters, oysters after 14 days in sites and oysters during the depuration processes: virus (HAdV, HAV, HuNoV GI/GII and JCPyV), by (RT) qPCR; protozoa (Cryptosporidium and Giardia species), by immunomagnetic separation and immunofluorescence; and organic compounds (AHs, PAHs, LABs, PCBs and organochlorine pesticides-OCs), by chromatography. Changes in the oysters' tissues produced by the depuration processes were also evaluated using histochemical analysis by light microscopy. In the artificially bioaccumulated oysters, only HAdV2 and MNV1 were investigated by (RT) qPCR before the depuration procedures and after 96 and 168 h of these procedures., Results: At 14 days post-allocation, HAdV was found in all the sites (6.2 × 105 to 4.4 × 107 GC g(-1)), and Giardia species in only one site. Levels of PCBs and OCs in the oyster's tissues were below the detection limit for all samples. AHs (3.5 to 4.4 μg g(-1)), PAHs (11 to 191 ng g(-1)) and LABs (57 to 751 ng g(-1)) were detected in the samples from 3 sites. During the depuration assays, we found HAdV, Giardia and Cryptosporidium species until 168 h, independent of UV treatment. AHs, PAHs and LABs were found also after 168 h of depuration (36 W and without UV lamp). The depuration procedures did not produce changes in the oysters' tissues. In the artificially contaminated and depurated oysters, we detected HAdV until 168 h and MNV1 until 96 h of depuration., Conclusion: The applied depuration treatments were unable to eliminate the protozoa or to degrade the HAdV genomes but were able to degrade the MNV1 genomes. Similarly, the UV water treatment was not efficient for aliphatic hydrocarbons, PAHs and LABs, as their concentrations were equivalent or higher to the concentrations of the control samples and samples from depuration tanks without UV treatment., (© 2013.)
- Published
- 2013
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49. Survival and ultrastructural features of peach palm (Bactris gasipaes, Kunth) somatic embryos submitted to cryopreservation through vitrification.
- Author
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Heringer AS, Steinmacher DA, Schmidt ÉC, Bouzon ZL, and Guerra MP
- Subjects
- Arecaceae cytology, Arecaceae genetics, Cryopreservation, Seeds cytology, Seeds genetics, Survival Analysis, Vitrification, Arecaceae embryology
- Abstract
Bactris gasipaes (Arecaceae), also known as peach palm, was domesticated by Amazonian Indians and is cultivated for its fruit and heart-of-palm, a vegetable grown in the tree's inner core. Currently, the conservation of this species relies on in situ conditions and field gene banks. Complementary conservation strategies, such as those based on in vitro techniques, are indicated in such cases. To establish an appropriate cryopreservation protocol, this study aimed to evaluate the ultrastructural features of B. gasipaes embryogenic cultures submitted to vitrification and subsequent cryogenic temperatures. Accordingly, somatic embryo clusters were submitted to Plant Vitrification Solution 3 (PVS3). In general, cells submitted to PVS3 had viable cell characteristics associated with apparently many mitochondria, prominent nucleus, and preserved cell walls. Cells not incubated in PVS3 did not survive after the cryogenic process in liquid nitrogen. The best incubation time for the vitrification technique was 240 min, resulting in a survival rate of 37 %. In these cases, several features were indicative of quite active cell metabolism, including intact nuclei and preserved cell walls, an apparently many of mitochondria and lipid bodies, and the presence of many starch granules and condensed chromatin. Moreover, ultrastructure analysis revealed that overall cellular structures had been preserved after cryogenic treatment, thus validating the use of vitrification in conjunction with cryopreservation of peach palm elite genotypes, as well as wild genotypes, which carry a rich pool of genes that must be conserved.
- Published
- 2013
- Full Text
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50. The effects of lead and copper on the cellular architecture and metabolism of the red alga Gracilaria domingensis.
- Author
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Gouveia C, Kreusch M, Schmidt ÉC, Felix MR, Osorio LK, Pereira DT, dos Santos R, Ouriques LC, Martins Rde P, Latini A, Ramlov F, Carvalho TJ, Chow F, Maraschin M, and Bouzon ZL
- Subjects
- Biomass, Carotenoids analysis, Cell Wall chemistry, Cell Wall drug effects, Cell Wall ultrastructure, Chlorophyll analysis, Chlorophyll A, Chloroplasts drug effects, Chloroplasts ultrastructure, Copper analysis, Cytoplasm chemistry, Electron Probe Microanalysis, Gracilaria growth & development, Gracilaria metabolism, Gracilaria ultrastructure, Lead analysis, Microscopy, Mitochondria drug effects, Mitochondria metabolism, Mitochondria ultrastructure, NADH Dehydrogenase metabolism, Photosynthesis drug effects, Phycobiliproteins analysis, Copper toxicity, Gracilaria drug effects, Lead toxicity
- Abstract
The effect of lead and copper on apical segments of Gracilaria domingensis was examined. Over a period of 7 days, the segments were cultivated with concentrations of 5 and 10 ppm under laboratory conditions. The samples were processed for light, confocal, and electron microscopy, as well as histochemistry, to evaluate growth rates, mitochondrial activity, protein levels, chlorophyll a, phycobiliproteins, and carotenoids. After 7 days of exposure to lead and copper, growth rates were slower than control, and biomass loss was observed on copper-treated plants. Ultrastructural damage was primarily observed in the internal organization of chloroplasts and cell wall thickness. X-ray microanalysis detected lead in the cell wall, while copper was detected in both the cytoplasm and cell wall. Moreover, lead and copper exposure led to photodamage of photosynthetic pigments and, consequently, changes in photosynthesis. However, protein content and glutathione reductase activity decreased only in the copper treatments. In both treatments, decreased mitochondrial NADH dehydrogenase activity was observed. Taken together, the present study demonstrates that (1) heavy metals such as lead and copper negatively affect various morphological, physiological, and biochemical processes in G. domingensis and (2) copper is more toxic than lead in G. domingensis.
- Published
- 2013
- Full Text
- View/download PDF
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