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Can Parietin Transfer Energy Radiatively to Photosynthetic Pigments?
The main role of lichen anthraquinones is in protection against biotic and abiotic stresses, such as UV radiation. These compounds are frequently deposited as crystals outside the fungal hyphae and most of them emit visible fluorescence when excited by UV. We wondered whether the conversion of UV in...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6099737/ https://www.ncbi.nlm.nih.gov/pubmed/30018202 http://dx.doi.org/10.3390/molecules23071741 |
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author | Fernández-Marín, Beatriz Artetxe, Unai Becerril, José María Martínez-Abaigar, Javier Núñez-Olivera, Encarnación García-Plazaola, José Ignacio |
author_facet | Fernández-Marín, Beatriz Artetxe, Unai Becerril, José María Martínez-Abaigar, Javier Núñez-Olivera, Encarnación García-Plazaola, José Ignacio |
author_sort | Fernández-Marín, Beatriz |
collection | PubMed |
description | The main role of lichen anthraquinones is in protection against biotic and abiotic stresses, such as UV radiation. These compounds are frequently deposited as crystals outside the fungal hyphae and most of them emit visible fluorescence when excited by UV. We wondered whether the conversion of UV into visible fluorescence might be photosynthetically used by the photobiont, thereby converting UV into useful energy. To address this question, thalli of Xanthoria parietina were used as a model system. In this species the anthraquinone parietin accumulates in the outer upper cortex, conferring the species its characteristic yellow-orange colouration. In ethanol, parietin absorbed strongly in the blue and UV-B and emitted fluorescence in the range 480–540 nm, which partially matches with the absorption spectra of photosynthetic pigments. In intact thalli, it was determined by confocal microscopy that fluorescence emission spectra shifted 90 nm towards longer wavelengths. Then, to study energy transfer from parietin, we compared the response to UV of untreated and parietin-free thalli (removed with acetone). A chlorophyll fluorescence kinetic assessment provided evidence of UV-induced electron transport, though independently of the presence of parietin. Thus, a role for anthraquinones in energy harvesting is not supported for X. parietina under presented experimental conditions. |
format | Online Article Text |
id | pubmed-6099737 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-60997372018-11-13 Can Parietin Transfer Energy Radiatively to Photosynthetic Pigments? Fernández-Marín, Beatriz Artetxe, Unai Becerril, José María Martínez-Abaigar, Javier Núñez-Olivera, Encarnación García-Plazaola, José Ignacio Molecules Communication The main role of lichen anthraquinones is in protection against biotic and abiotic stresses, such as UV radiation. These compounds are frequently deposited as crystals outside the fungal hyphae and most of them emit visible fluorescence when excited by UV. We wondered whether the conversion of UV into visible fluorescence might be photosynthetically used by the photobiont, thereby converting UV into useful energy. To address this question, thalli of Xanthoria parietina were used as a model system. In this species the anthraquinone parietin accumulates in the outer upper cortex, conferring the species its characteristic yellow-orange colouration. In ethanol, parietin absorbed strongly in the blue and UV-B and emitted fluorescence in the range 480–540 nm, which partially matches with the absorption spectra of photosynthetic pigments. In intact thalli, it was determined by confocal microscopy that fluorescence emission spectra shifted 90 nm towards longer wavelengths. Then, to study energy transfer from parietin, we compared the response to UV of untreated and parietin-free thalli (removed with acetone). A chlorophyll fluorescence kinetic assessment provided evidence of UV-induced electron transport, though independently of the presence of parietin. Thus, a role for anthraquinones in energy harvesting is not supported for X. parietina under presented experimental conditions. MDPI 2018-07-17 /pmc/articles/PMC6099737/ /pubmed/30018202 http://dx.doi.org/10.3390/molecules23071741 Text en © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Communication Fernández-Marín, Beatriz Artetxe, Unai Becerril, José María Martínez-Abaigar, Javier Núñez-Olivera, Encarnación García-Plazaola, José Ignacio Can Parietin Transfer Energy Radiatively to Photosynthetic Pigments? |
title | Can Parietin Transfer Energy Radiatively to Photosynthetic Pigments? |
title_full | Can Parietin Transfer Energy Radiatively to Photosynthetic Pigments? |
title_fullStr | Can Parietin Transfer Energy Radiatively to Photosynthetic Pigments? |
title_full_unstemmed | Can Parietin Transfer Energy Radiatively to Photosynthetic Pigments? |
title_short | Can Parietin Transfer Energy Radiatively to Photosynthetic Pigments? |
title_sort | can parietin transfer energy radiatively to photosynthetic pigments? |
topic | Communication |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6099737/ https://www.ncbi.nlm.nih.gov/pubmed/30018202 http://dx.doi.org/10.3390/molecules23071741 |
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