New insight into silica deposition in horsetail (Equisetum arvense)

BACKGROUND: The horsetails (Equisetum sp) are known biosilicifiers though the mechanism underlying silica deposition in these plants remains largely unknown. Tissue extracts from horsetails grown hydroponically and also collected from the wild were acid-digested in a microwave oven and their silica...

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Autores principales: Law, Chinnoi, Exley, Christopher
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3160890/
https://www.ncbi.nlm.nih.gov/pubmed/21801378
http://dx.doi.org/10.1186/1471-2229-11-112
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author Law, Chinnoi
Exley, Christopher
author_facet Law, Chinnoi
Exley, Christopher
author_sort Law, Chinnoi
collection PubMed
description BACKGROUND: The horsetails (Equisetum sp) are known biosilicifiers though the mechanism underlying silica deposition in these plants remains largely unknown. Tissue extracts from horsetails grown hydroponically and also collected from the wild were acid-digested in a microwave oven and their silica 'skeletons' visualised using the fluor, PDMPO, and fluorescence microscopy. RESULTS: Silica deposits were observed in all plant regions from the rhizome through to the stem, leaf and spores. Numerous structures were silicified including cell walls, cell plates, plasmodesmata, and guard cells and stomata at varying stages of differentiation. All of the major sites of silica deposition in horsetail mimicked sites and structures where the hemicellulose, callose is known to be found and these serendipitous observations of the coincidence of silica and callose raised the possibility that callose might be templating silica deposition in horsetail. Hydroponic culture of horsetail in the absence of silicic acid resulted in normal healthy plants which, following acid digestion, showed no deposition of silica anywhere in their tissues. To test the hypothesis that callose might be templating silica deposition in horsetail commercially available callose was mixed with undersaturated and saturated solutions of silicic acid and the formation of silica was demonstrated by fluorimetry and fluorescence microscopy. CONCLUSIONS: The initiation of silica formation by callose is the first example whereby any biomolecule has been shown to induce, as compared to catalyse, the formation of silica in an undersaturated solution of silicic acid. This novel discovery allowed us to speculate that callose and its associated biochemical machinery could be a missing link in our understanding of biosilicification.
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spelling pubmed-31608902011-08-25 New insight into silica deposition in horsetail (Equisetum arvense) Law, Chinnoi Exley, Christopher BMC Plant Biol Research Article BACKGROUND: The horsetails (Equisetum sp) are known biosilicifiers though the mechanism underlying silica deposition in these plants remains largely unknown. Tissue extracts from horsetails grown hydroponically and also collected from the wild were acid-digested in a microwave oven and their silica 'skeletons' visualised using the fluor, PDMPO, and fluorescence microscopy. RESULTS: Silica deposits were observed in all plant regions from the rhizome through to the stem, leaf and spores. Numerous structures were silicified including cell walls, cell plates, plasmodesmata, and guard cells and stomata at varying stages of differentiation. All of the major sites of silica deposition in horsetail mimicked sites and structures where the hemicellulose, callose is known to be found and these serendipitous observations of the coincidence of silica and callose raised the possibility that callose might be templating silica deposition in horsetail. Hydroponic culture of horsetail in the absence of silicic acid resulted in normal healthy plants which, following acid digestion, showed no deposition of silica anywhere in their tissues. To test the hypothesis that callose might be templating silica deposition in horsetail commercially available callose was mixed with undersaturated and saturated solutions of silicic acid and the formation of silica was demonstrated by fluorimetry and fluorescence microscopy. CONCLUSIONS: The initiation of silica formation by callose is the first example whereby any biomolecule has been shown to induce, as compared to catalyse, the formation of silica in an undersaturated solution of silicic acid. This novel discovery allowed us to speculate that callose and its associated biochemical machinery could be a missing link in our understanding of biosilicification. BioMed Central 2011-07-29 /pmc/articles/PMC3160890/ /pubmed/21801378 http://dx.doi.org/10.1186/1471-2229-11-112 Text en Copyright ©2011 Law and Exley; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Law, Chinnoi
Exley, Christopher
New insight into silica deposition in horsetail (Equisetum arvense)
title New insight into silica deposition in horsetail (Equisetum arvense)
title_full New insight into silica deposition in horsetail (Equisetum arvense)
title_fullStr New insight into silica deposition in horsetail (Equisetum arvense)
title_full_unstemmed New insight into silica deposition in horsetail (Equisetum arvense)
title_short New insight into silica deposition in horsetail (Equisetum arvense)
title_sort new insight into silica deposition in horsetail (equisetum arvense)
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3160890/
https://www.ncbi.nlm.nih.gov/pubmed/21801378
http://dx.doi.org/10.1186/1471-2229-11-112
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