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Coloration of Flowers by Flavonoids and Consequences of pH Dependent Absorption

Flavonoid pigments are key determinants of flower colors. As absorption spectra of flavonoids are known to be severely pH-dependent, cellular pH will play a crucial role in flower coloration. The flavonoids are concentrated in the vacuoles of the flowers’ epidermal cells, and thus the pigments’ abso...

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Autores principales: Stavenga, Doekele G., Leertouwer, Hein L., Dudek, Bettina, van der Kooi, Casper J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7820715/
https://www.ncbi.nlm.nih.gov/pubmed/33488645
http://dx.doi.org/10.3389/fpls.2020.600124
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author Stavenga, Doekele G.
Leertouwer, Hein L.
Dudek, Bettina
van der Kooi, Casper J.
author_facet Stavenga, Doekele G.
Leertouwer, Hein L.
Dudek, Bettina
van der Kooi, Casper J.
author_sort Stavenga, Doekele G.
collection PubMed
description Flavonoid pigments are key determinants of flower colors. As absorption spectra of flavonoids are known to be severely pH-dependent, cellular pH will play a crucial role in flower coloration. The flavonoids are concentrated in the vacuoles of the flowers’ epidermal cells, and thus the pigments’ absorption spectra are modulated by the vacuolar pH. Here we study the pH dependence of flavonoid absorption spectra in extracts from flowers of two poppy species Papaver dubium (red) and Meconopsis cambrica (orange), and a white and red Mandevilla sanderi variety. In the red poppy and Mandevilla flowers, absorption spectra of the cyanidin- and pelargonidin-based anthocyanins peak in the blue-green-wavelength range at low pH, but exhibit a distinct bathochromic shift at higher pH. This shift to longer wavelengths is not found for the blue-absorbing nudicaulin derivatives of M. cambrica, which have a similar absorption spectrum at low and high pH. The pH-dependent absorption changes of the white M. sanderi’s flavonoid remained restricted to the UV. An analysis of the spectra with logistic functions suggests that the pH-dependent characteristics of the basic states of flavonols and anthocyanins are related. The implications of tuning of pH and pigment absorption spectra for studies on flower color evolution are discussed.
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spelling pubmed-78207152021-01-23 Coloration of Flowers by Flavonoids and Consequences of pH Dependent Absorption Stavenga, Doekele G. Leertouwer, Hein L. Dudek, Bettina van der Kooi, Casper J. Front Plant Sci Plant Science Flavonoid pigments are key determinants of flower colors. As absorption spectra of flavonoids are known to be severely pH-dependent, cellular pH will play a crucial role in flower coloration. The flavonoids are concentrated in the vacuoles of the flowers’ epidermal cells, and thus the pigments’ absorption spectra are modulated by the vacuolar pH. Here we study the pH dependence of flavonoid absorption spectra in extracts from flowers of two poppy species Papaver dubium (red) and Meconopsis cambrica (orange), and a white and red Mandevilla sanderi variety. In the red poppy and Mandevilla flowers, absorption spectra of the cyanidin- and pelargonidin-based anthocyanins peak in the blue-green-wavelength range at low pH, but exhibit a distinct bathochromic shift at higher pH. This shift to longer wavelengths is not found for the blue-absorbing nudicaulin derivatives of M. cambrica, which have a similar absorption spectrum at low and high pH. The pH-dependent absorption changes of the white M. sanderi’s flavonoid remained restricted to the UV. An analysis of the spectra with logistic functions suggests that the pH-dependent characteristics of the basic states of flavonols and anthocyanins are related. The implications of tuning of pH and pigment absorption spectra for studies on flower color evolution are discussed. Frontiers Media S.A. 2021-01-08 /pmc/articles/PMC7820715/ /pubmed/33488645 http://dx.doi.org/10.3389/fpls.2020.600124 Text en Copyright © 2021 Stavenga, Leertouwer, Dudek and van der Kooi. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Plant Science
Stavenga, Doekele G.
Leertouwer, Hein L.
Dudek, Bettina
van der Kooi, Casper J.
Coloration of Flowers by Flavonoids and Consequences of pH Dependent Absorption
title Coloration of Flowers by Flavonoids and Consequences of pH Dependent Absorption
title_full Coloration of Flowers by Flavonoids and Consequences of pH Dependent Absorption
title_fullStr Coloration of Flowers by Flavonoids and Consequences of pH Dependent Absorption
title_full_unstemmed Coloration of Flowers by Flavonoids and Consequences of pH Dependent Absorption
title_short Coloration of Flowers by Flavonoids and Consequences of pH Dependent Absorption
title_sort coloration of flowers by flavonoids and consequences of ph dependent absorption
topic Plant Science
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7820715/
https://www.ncbi.nlm.nih.gov/pubmed/33488645
http://dx.doi.org/10.3389/fpls.2020.600124
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