Fungal spore germination: Insights from the molecular genetics of Aspergillus nidulans and Neurospora crassa

Spore germination is an essential developmental stage in the life cycle of all filamentous fungi. Three important steps can be distinguished during spore germination: activation of the resting spore in response to appropriate environmental conditions, isotropic growth that involves water uptake and the resumption of numerous metabolic activities, and polarized growth that results in the formation of a germ tube from which the new mycelium originates. Recent molecular genetics studies have brought new information regarding the participation of different cellular processes (trehalose metabolism, gene expression, cell wall biogenesis, cell cycle) in the control of conidial germination in two model filamentous ascomycetes, Aspergillus nidulans and Neurospora crassa. Although the mechanisms of fungal spore germination still remain unclear, new research directions emerge that will contribute answers to more general questions of cell biology. (C) 1997 Academic Press.