Zancajo Victor M R, Diehn Sabrina, Filiba Nurit, Goobes Gil, Kneipp Janina, Elbaum Rivka
School of Analytical Sciences Adlershof (SALSA), Humboldt-Universität zu Berlin, Berlin, Germany.
Chemistry Department, Humboldt-Universität zu Berlin, Berlin, Germany.
Front Plant Sci. 2019 Dec 11;10:1571. doi: 10.3389/fpls.2019.01571. eCollection 2019.
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 (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.
禾本科植物以硅酸的形式积累硅，硅酸会以无定形二氧化硅的形式沉淀在称为植硅体的微观颗粒中。根据硅沉积所在的细胞类型，这些颗粒具有多种形态。尽管形态差异明显，但植硅体化学大多是在大量样本中进行分析的，忽略了同一物种中形成的不同类型之间的差异。在这项工作中，我们从黑高粱（L.）Moench的成熟植株中提取了叶片植硅体。通过固态核磁共振和热重分析，我们表明提取方法极大地改变了二氧化硅的分子结构、其缩合程度以及捕获的有机物。通过拉曼光谱和同步加速器傅里叶变换红外显微光谱对单个植硅体进行测量，并结合多变量分析，基于二氧化硅分子结构以及封闭有机物的含量和组成，将双叶形硅细胞与刺和长细胞区分开来。高粱植硅体在结构和组成上的变化表明，导致硅沉积的生物学途径在这些细胞类型之间存在差异。
