Subcellular Localization of Glucanase and Cellulase in Saprolegnia monoica Pringsheim

Abstract

(I .fwdarw. 3)-.beta.-Glucanase [EC 3.2.1.6] and cellulase [EC 3.2.1.4], thought to be involved in the growth and branching processes of S. monoica hyphae, were mainly localized at the edge of the colony. Autolysis of purified cell walls occurred preferentially in newly-formed walls. This process was more important in walls of branched hyphae than in those of unbranched mycelium. Intracellular fractions were separated and characterized by density gradient ultracentrifugation, enzymic tests and EM. The fractions rich in .beta.-glucanase and cellulase contained dictyosomes and apical vesicles. In agreement with cytological descriptions of the apex, the results confirm the role of these morphogen enzymes in hyphal morphogenesis.