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H(2)O(2) localization in the green alga Micrasterias after salt and osmotic stress by TEM-coupled electron energy loss spectroscopy

Reactive oxygen species (ROS), including hydrogen peroxide (H(2)O(2)), are constantly generated as by-products of normal metabolic cellular pathways and can be overproduced in response to stress. In this study, we investigated ROS production and localization of H(2)O(2) after salt (200 mM KCl) and o...

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Autores principales: Darehshouri, Anza, Lütz-Meindl, Ursula
Formato: Texto
Lenguaje:English
Publicado: Springer Vienna 2009
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2826641/
https://www.ncbi.nlm.nih.gov/pubmed/19902325
http://dx.doi.org/10.1007/s00709-009-0081-4
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author Darehshouri, Anza
Lütz-Meindl, Ursula
author_facet Darehshouri, Anza
Lütz-Meindl, Ursula
author_sort Darehshouri, Anza
collection PubMed
description Reactive oxygen species (ROS), including hydrogen peroxide (H(2)O(2)), are constantly generated as by-products of normal metabolic cellular pathways and can be overproduced in response to stress. In this study, we investigated ROS production and localization of H(2)O(2) after salt (200 mM KCl) and osmotic (iso-osmotic sorbitol concentration) stress in the unicellular green alga Micrasterias. By means of the dye H(2)DCFDA and confocal laser scanning microscopy, most ROS production could be detected in KCl-treated cells when compared to sorbitol-exposed cells and controls. For ultrastructural detection of H(2)O(2), CeCl(3), which reacts with H(2)O(2) and produces cerium perhydroxide deposits, has been used. Cerium was identified by transmission electron microscopy (TEM)-coupled electron energy loss spectroscopy (EELS) in organelles of KCl- and sorbitol-treated cells and in controls. Statistical measurements of the presence of the cerium M(4,5) edge were performed in mitochondria, chloroplasts, cell walls, and cytoplasmic sites of five individual cells after each treatment. The most pronounced increase in H(2)O(2) production was found in chloroplasts of KCl- and sorbitol-treated cells. This shows that the chloroplast reveals the strongest response in H(2)O(2) production after stress induction in Micrasterias. Significant elevation of H(2)O(2) production also occurred in mitochondria and cytoplasm, whereas H(2)O(2) levels remained unchanged or even slightly decreased in cell walls of treated cells. Additionally, TEM micrographs and EELS analyses provided indirect evidence for an increased H(2)O(2) production at the plasma membrane of KCl-treated cells, indicating an involvement of the plasma membrane NADPH oxidase in H(2)O(2) generation.
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spelling pubmed-28266412010-03-05 H(2)O(2) localization in the green alga Micrasterias after salt and osmotic stress by TEM-coupled electron energy loss spectroscopy Darehshouri, Anza Lütz-Meindl, Ursula Protoplasma Original Article Reactive oxygen species (ROS), including hydrogen peroxide (H(2)O(2)), are constantly generated as by-products of normal metabolic cellular pathways and can be overproduced in response to stress. In this study, we investigated ROS production and localization of H(2)O(2) after salt (200 mM KCl) and osmotic (iso-osmotic sorbitol concentration) stress in the unicellular green alga Micrasterias. By means of the dye H(2)DCFDA and confocal laser scanning microscopy, most ROS production could be detected in KCl-treated cells when compared to sorbitol-exposed cells and controls. For ultrastructural detection of H(2)O(2), CeCl(3), which reacts with H(2)O(2) and produces cerium perhydroxide deposits, has been used. Cerium was identified by transmission electron microscopy (TEM)-coupled electron energy loss spectroscopy (EELS) in organelles of KCl- and sorbitol-treated cells and in controls. Statistical measurements of the presence of the cerium M(4,5) edge were performed in mitochondria, chloroplasts, cell walls, and cytoplasmic sites of five individual cells after each treatment. The most pronounced increase in H(2)O(2) production was found in chloroplasts of KCl- and sorbitol-treated cells. This shows that the chloroplast reveals the strongest response in H(2)O(2) production after stress induction in Micrasterias. Significant elevation of H(2)O(2) production also occurred in mitochondria and cytoplasm, whereas H(2)O(2) levels remained unchanged or even slightly decreased in cell walls of treated cells. Additionally, TEM micrographs and EELS analyses provided indirect evidence for an increased H(2)O(2) production at the plasma membrane of KCl-treated cells, indicating an involvement of the plasma membrane NADPH oxidase in H(2)O(2) generation. Springer Vienna 2009-11-10 2010 /pmc/articles/PMC2826641/ /pubmed/19902325 http://dx.doi.org/10.1007/s00709-009-0081-4 Text en © The Author(s) 2009 https://creativecommons.org/licenses/by-nc/4.0/ This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.
spellingShingle Original Article
Darehshouri, Anza
Lütz-Meindl, Ursula
H(2)O(2) localization in the green alga Micrasterias after salt and osmotic stress by TEM-coupled electron energy loss spectroscopy
title H(2)O(2) localization in the green alga Micrasterias after salt and osmotic stress by TEM-coupled electron energy loss spectroscopy
title_full H(2)O(2) localization in the green alga Micrasterias after salt and osmotic stress by TEM-coupled electron energy loss spectroscopy
title_fullStr H(2)O(2) localization in the green alga Micrasterias after salt and osmotic stress by TEM-coupled electron energy loss spectroscopy
title_full_unstemmed H(2)O(2) localization in the green alga Micrasterias after salt and osmotic stress by TEM-coupled electron energy loss spectroscopy
title_short H(2)O(2) localization in the green alga Micrasterias after salt and osmotic stress by TEM-coupled electron energy loss spectroscopy
title_sort h(2)o(2) localization in the green alga micrasterias after salt and osmotic stress by tem-coupled electron energy loss spectroscopy
topic Original Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2826641/
https://www.ncbi.nlm.nih.gov/pubmed/19902325
http://dx.doi.org/10.1007/s00709-009-0081-4
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