MORPHOGENESIS AND MECHANISMS OF PENETRATION BY PLANT-PATHOGENIC FUNGI

Infection structures of phytopathogenic fungi are modified hyphae spec ialized for the invasion of plant tissues. Initial events are adhesion to the cuticle and directed growth of the germ tube on the plant surf ace. At the site of penetration, appressoria are often formed that may have melanized walls and develop high turgor pressure to support the penetration process. The penetration hypha accumulates components of t he cytoskeleton in the tip and secretes a variety of cell wall-degradi ng enzymes in a highly regulated fashion in order to penetrate the cut icle and the plant cell wall. This article reviews recent papers on th e cytology, physiology, and molecular biology of the penetration proce ss.