[Experiments on the analysis of the development of the protonema of mosses : IV. The endogenous factor H and its role in the morphogenesis of Funaria hygrometrica]

Abstract

1. Differentiations in the protonema of Funaria hygrometrica are greatly influenced by substances which the protonema itself releases into the substrate. 2. The radial symmetric field of diffusion of these substances causes the "fairy ring". 3. Factor H is the first of these morphogenetic substances produced by the protonema to be isolated from the substrate. This factor may be considered as a hormone and is responsible primarily for the bud-formation in caulonema. The inhibition of caulonema growth is a secondary effect of factor H and therefore of subordinate importance; in any case, this effect shows no direct correlation to the induction of bud formation. Factor H is first released into the substrate at the beginning of caulonema differentiation. Later on it can be obtained by suspending some protonema in nutrient solution. 4. Factor H is stable at 100°C and is soluble in water, butyl alcohol, amyl alcohol and ethyl acetate. In the presence of water the solubility in ethyl acetate depends on the pH of the solution. Factor H is easily soluble at pH 2-7, soluble at pH 7-9 and insoluble at pH values above 9. At pH 3-9, factor H exists as a cation and therefore it can be purified by electrophoresis or by cation-exchange chromatography.