Freeze-fracture and Freeze-etching Study of Encystment of Phytophthora palmivora Zoospores

Abstract

Zoospores of P. palmivora were induced to encyst synchronously and changes in morphology, particularly in surface structure, were examined by freeze-fracture and freeze-etching techniques. A uniform fuzzy coat, 20-25 nm thick, covers the plasma membrane. This hitherto unknown structure surrounds the entire zoospore body and flagella. No structural correspondence between cyst wall microfibrils and plasma membrane particles was found. The pattern of distribution of plasma membrane particles remains unchanged during encystment.