TY - JOUR A1 - Zancajo, V. M. R. A1 - Lindtner, T. A1 - Eisele, M. A1 - Huber, A. J. A1 - Elbaum, R. A1 - Kneipp, Janina T1 - FTIR Nanospectroscopy Shows Molecular Structures of Plant Biominerals and Cell Walls N2 - Plant tissues are complex composite structures of organic and inorganic components whose function relies on molecular heterogeneity at the nanometer scale. Scattering-type near-field optical microscopy (s-SNOM) in the mid-infrared (IR) region is used here to collect IR nanospectra from both fixed and native plant samples. We compared structures of chemically extracted silica bodies (phytoliths) to silicified and nonsilicified cell walls prepared as a flat block of epoxy-embedded awns of wheat (Triticum turgidum), thin sections of native epidermis cells from sorghum (Sorghum bicolor) comprising silica phytoliths, and isolated cells from awns of oats (Avena sterilis). The correlation of the scanning-probe IR images and the mechanical phase image enables a combined probing of mechanical material properties together with the chemical composition and structure of both the cell walls and the phytolith structures. The data reveal a structural heterogeneity of the different silica bodies in situ, as well as different compositions and crystallinities of cell wall components. In conclusion, IR nanospectroscopy is suggested as an ideal tool for studies of native plant materials of varied origins and preparations and could be applied to other inorganic–organic hybrid materials. KW - Cells KW - Plants KW - Organic polymers KW - Silica KW - Infrared light PY - 2020 DO - https://doi.org/10.1021/acs.analchem.0c00271 SN - 0003-2700 VL - 92 IS - 20 SP - 13694 EP - 13701 PB - ACS Publications AN - OPUS4-54445 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kneipp, Janina A1 - Zancajo, Victor M.R. A1 - Diehn, S. A1 - Filiba, N. A1 - Elbaum, R. T1 - Spectroscopic Discrimination of Sorghum Silica Phytoliths N2 - Grasses accumulate silicon in the form of silicic acid, which is precipitated as amorphous silica in microscopic particles termed phytoliths. These particles comprise a variety of morphologies according to the cell type in which the silica was deposited. Despite the evident morphological differences, phytolith chemistry has mostly been analysed in bulk samples, neglecting differences between the varied types formed in the same species. In this work, we extracted leaf phytoliths from mature plants of Sorghum bicolor (L.) Moench. Using solid state NMR and thermogravimetric analysis, we show that the extraction methods alter greatly the silica molecular structure, its condensation degree and the trapped organic matter. Measurements of individual phytoliths by Raman and synchrotron FTIR microspectroscopies in combination with multivariate analysis separated bilobate silica cells from prickles and long cells, based on the silica molecular structures and the fraction and composition of occluded organic matter. The variations in structure and composition of sorghum phytoliths suggest that the biological pathways leading to silica deposition vary between these cell types. KW - Phytoliths KW - Biosilicification KW - Raman KW - Sorghum KW - Solid state NMR KW - Synchrotron FTIR PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-502672 DO - https://doi.org/10.3389/fpls.2019.01571 VL - 10 SP - 1571 PB - Frontiers Media CY - Lausanne AN - OPUS4-50267 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -