Changes in cell wall structure during the protonema development on organic medium in conditions of light and darkness in Funaria hygrometrica

Abstract

The cell walls of a protonema of <i>Funaria hygrometrica</i> cultivated in glucose containing medium were considerably thicker in dark than in light. After a prolonged time of dank culture, a considerable reduction of the wall thicknes was observed, simultaneously with the occurrence of vesicles and plasmalemma invaginations containing fibrillar material. It is suggested that in conditions unfavourable for growth, the sugar taken up from the medium can be accumulated in cell walls, from which it can be mobilized again in conditions of starvation. The authors also think that similar mechanism and cell structures can be involved in both building and decomposition of the cell wall.