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Are Freshwater Mixotrophic Ciliates Less Sensitive to Solar Ultraviolet Radiation than Heterotrophic Ones?1

We tested whether mixotrophic ciliates are more resistant to solar ultraviolet radiation (UVR) than heterotrophic ones because symbiotic algae can provide self-shading by cell matter absorption and eventually by direct UV screening from mycosporine-like amino acids (MAAs). Sensitivity of a natural a...

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Autores principales: SONNTAG, BETTINA, SUMMERER, MONIKA, SOMMARUGA, RUBEN
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Blackwell Publishing Inc 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3182536/
https://www.ncbi.nlm.nih.gov/pubmed/21414057
http://dx.doi.org/10.1111/j.1550-7408.2011.00540.x
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author SONNTAG, BETTINA
SUMMERER, MONIKA
SOMMARUGA, RUBEN
author_facet SONNTAG, BETTINA
SUMMERER, MONIKA
SOMMARUGA, RUBEN
author_sort SONNTAG, BETTINA
collection PubMed
description We tested whether mixotrophic ciliates are more resistant to solar ultraviolet radiation (UVR) than heterotrophic ones because symbiotic algae can provide self-shading by cell matter absorption and eventually by direct UV screening from mycosporine-like amino acids (MAAs). Sensitivity of a natural assemblage to solar radiation was tested in experiments in the original lake and in a more UV transparent alpine lake after transplantation of the ciliates. In both lakes, the assemblage was exposed either to full sunlight, to photosynthetically active radiation only, or kept in the dark. In each lake, exposure was for 5 h at the surface and at the depth corresponding to the 10% attenuation depth at 320 nm. Overall, when the assemblage was exposed to surface UVR, only one out of four dominant mixotrophic ciliates, Vorticella chlorellata, was more resistant than heterotrophic species. The higher UV resistance in V. chlorellata was related to the presence of MAAs and the high percentage of ciliate volume occupied by algal symbionts. Our results indicate that effects of UVR were species-specific and depended on efficient screening of these wavelengths, but also on the depth preference of the ciliates and thus, on their previous exposure history to UVR.
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spelling pubmed-31825362011-09-29 Are Freshwater Mixotrophic Ciliates Less Sensitive to Solar Ultraviolet Radiation than Heterotrophic Ones?1 SONNTAG, BETTINA SUMMERER, MONIKA SOMMARUGA, RUBEN J Eukaryot Microbiol Symposium: Alternative Nutritional Strategies in Protists We tested whether mixotrophic ciliates are more resistant to solar ultraviolet radiation (UVR) than heterotrophic ones because symbiotic algae can provide self-shading by cell matter absorption and eventually by direct UV screening from mycosporine-like amino acids (MAAs). Sensitivity of a natural assemblage to solar radiation was tested in experiments in the original lake and in a more UV transparent alpine lake after transplantation of the ciliates. In both lakes, the assemblage was exposed either to full sunlight, to photosynthetically active radiation only, or kept in the dark. In each lake, exposure was for 5 h at the surface and at the depth corresponding to the 10% attenuation depth at 320 nm. Overall, when the assemblage was exposed to surface UVR, only one out of four dominant mixotrophic ciliates, Vorticella chlorellata, was more resistant than heterotrophic species. The higher UV resistance in V. chlorellata was related to the presence of MAAs and the high percentage of ciliate volume occupied by algal symbionts. Our results indicate that effects of UVR were species-specific and depended on efficient screening of these wavelengths, but also on the depth preference of the ciliates and thus, on their previous exposure history to UVR. Blackwell Publishing Inc 2011-05 /pmc/articles/PMC3182536/ /pubmed/21414057 http://dx.doi.org/10.1111/j.1550-7408.2011.00540.x Text en 2011 The Author(s). Journal of Eukaryotic Microbiology © 2011 International Society of Protistologists http://creativecommons.org/licenses/by/2.5/ Re-use of this article is permitted in accordance with the Terms and Conditions set out at http://wileyonlinelibrary.com/onlineopen#OnlineOpen_Terms.
spellingShingle Symposium: Alternative Nutritional Strategies in Protists
SONNTAG, BETTINA
SUMMERER, MONIKA
SOMMARUGA, RUBEN
Are Freshwater Mixotrophic Ciliates Less Sensitive to Solar Ultraviolet Radiation than Heterotrophic Ones?1
title Are Freshwater Mixotrophic Ciliates Less Sensitive to Solar Ultraviolet Radiation than Heterotrophic Ones?1
title_full Are Freshwater Mixotrophic Ciliates Less Sensitive to Solar Ultraviolet Radiation than Heterotrophic Ones?1
title_fullStr Are Freshwater Mixotrophic Ciliates Less Sensitive to Solar Ultraviolet Radiation than Heterotrophic Ones?1
title_full_unstemmed Are Freshwater Mixotrophic Ciliates Less Sensitive to Solar Ultraviolet Radiation than Heterotrophic Ones?1
title_short Are Freshwater Mixotrophic Ciliates Less Sensitive to Solar Ultraviolet Radiation than Heterotrophic Ones?1
title_sort are freshwater mixotrophic ciliates less sensitive to solar ultraviolet radiation than heterotrophic ones?1
topic Symposium: Alternative Nutritional Strategies in Protists
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3182536/
https://www.ncbi.nlm.nih.gov/pubmed/21414057
http://dx.doi.org/10.1111/j.1550-7408.2011.00540.x
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