The Regulation of Silica Incorporation Into the Stinging Cell Wall of Urtica Pilulifera

Abstract

Silicification in biological systems results from the polymerization of silicic acid (Si(OH)4) monomers (1). It has been reported (2) that silification takes place in a very characteristic way in the stinging cell wall(Fig. 1, arrow) of the “Stinging Nettle” (Urtica pilulifera). The cell wall is composed of an organic and an inorganic (silica) component, and the latter occurs in two phases: matrix and particulate (Figs. 2, 3, and 4).It can be postulated that macromolecular assembly in biological systems involves proteins with both catalytic and regulatory sites which probably have different substrate specificities and sensitivities. Germanic acid and several silanes with organic functional groups substituted in place of one or more of the hydroxyl groups in silicic acid are easily prepared from commercially available compounds. Such compounds make ideal analogues by which the regulation of this unique silicification can be studied.