Studies on the biochemistry and fine structure of silica shell formation in diatoms: II. Changes in concentration of nucleoside triphosphates in silicon-starvation synchrony of Navicula pelliculosa (Bréb.) Hilse

Abstract

To assess the participation of NTP in the silicon metabolism of diatom cell wall formation, cultures of the freshwater diatom, Navicula pelliculosa were subjected to a period of silicon-starvation which blocks the division cycle after mitosis and cytokinesis have taken place. The addition of silicon induces synchronous silicon uptake, wall formation and cell separation. When silicon was resupplied to the silicon-deficient cultures, a rapid temporary increase, followed by a deep decrease in NTP concentration occurred during the first hour. NTP then increased throughout the remainder of the silicon uptake period. Similar changes occurred in a synchronous culture kept in the dark. This study confirms previous indications that NTP, and hence energy, is utilized in the biochemical processes of silicon metabolism in wall formation.