title: Silica accumulation in Triticum aestivum L. and Dactylis glomerata L.
abstract: The silica accumulation in orchard grass (Dactylis glomerata L.) and wheat (Triticum aestivum L.) has been studied in plant samples grown under defined conditions in a pot trial. The plant habit and the quantity of biomineralised silica within the selected Gramineae depend to a remarkable extent on the soil. The plants grew with different soil pH values and silica additives. By means of atomic absorption spectrometry, the silicon enrichment in different plant parts was determined. In dried plant parts the silica bodies can be well distinguished by variable pressure scanning electron microscopy in the back scattering mode. They are located in silica cells below the epidermis and in epidermal appendices (bristles, prickle hairs). The silica bodies showed a defined morphology, structure and composition which was elucidated by the combined performance of scanning electron microscopy in combination with X-ray spectroscopy, solid-state nuclear resonance, X-ray diffraction and Raman spectroscopy. The composition was near to stoichiometric SiO(2) (41 weight% silicon, 56 weight % oxygen), and the SiO(4/2)tetrahedra were arranged preferentially in three-dimensional networks; a smaller proportion was in chains and layers. The silica bodies with an overall amorphous structure contained crystalline precipitates, which could be indexed by alpha-quartz.
authors.affiliation: Institute of Chemistry, Technische Universität Chemnitz, Germany. dagmar.dietrich@chemie.tu-chemnitz.de
authors.forename: Dagmar
authors.initials: D
authors.lastname: Dietrich
authors.forename: Simone
authors.initials: S
authors.lastname: Hinke
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Baumann
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Fehlhaber
authors.forename: Ernst
authors.initials: E
authors.lastname: Bäucker
authors.forename: Gebhardt
authors.initials: G
authors.lastname: Rühle
authors.forename: Otto
authors.initials: O
authors.lastname: Wienhaus
authors.forename: Günter
authors.initials: G
authors.lastname: Marx
mesh_terms: D031745:Dactylis / Q000378:metabolism*; D004577:Electron Probe Microanalysis; D008855:Microscopy, Electron, Scanning; D012822:Silicon Dioxide / Q000378:metabolism*; D014908:Triticum / Q000378:metabolism*; D014961:X-Ray Diffraction
chemical_list: D012822:Silicon Dioxide