Original Research ARTICLE
Distributions of silica and biopolymer structural components in the spore elater of Equisetum arvense, an ancient silicifying plant
- 1Nottingham Trent University, United Kingdom
Equisetum species are primitive vascular plants that benefit from the biogenesis of silica bio-organic inclusions in their tissues and participate in the annual biosilica turnover in local eco-systems. As means of Equisetum reproduction and propagation, spores are expected to reflect the evolutionary adaptation of the plants to the climatic conditions at different times of the year. Combining methods of Raman and scanning electron microscopy and assisted with density functional theory, we conducted material spatial-spectral correlations to characterise the distribution of biopolymers and silica based structural elements that contribute to the bio-mineral content of the elater. The elater tip has underlying skeletal-like structural elements where cellulose fibres provide strength and flexibility, both of which are necessary for locomotion. The surface of the elater tips is rich with less ordered pectin like polysaccharide and shows a ridged, folded character. At the surface we observe silica of amorphous, colloidal form in nearly spherical structures where the silica is only a few layers thick. We propose the observed expansion of elater tips upon germination and the form of silica including encapsulated biopolymers are designed for ready dispersion, release of the polysaccharide-arginine rich content and to facilitate silica uptake to the developing plant. This behaviour would help to condition local soil chemistry to facilitate competitive rooting potential and stem propagation.
Keywords: Equisetum, spore, Germination, silica, Microscopy, Raman, DFT
Received: 13 Dec 2018;
Accepted: 07 Feb 2019.
Edited by:Martin J. Hodson, Oxford Brookes University, United Kingdom
Reviewed by:Christopher Exley, Keele University, United Kingdom
Richard Belanger, Laval University, Canada
Copyright: © 2019 Volkov, Hickman, Rabada and Perry. 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.
* Correspondence: Prof. Carole C. Perry, Nottingham Trent University, Nottingham, NG1 4BU, United Kingdom, firstname.lastname@example.org