Control of development in Neurospora crassa: Nutrient requirements for conidial germ tube emergence, elongation, and metabolic activation

Abstract

Spores incubated in media containing only the carbon source (sucrose) undergo a normal increase in polysomes although they do not undergo normal germ tube emergence. Spores incubated in sucrose-only medium for 3 h exhibit a decreased polysome content relative to spores incubated in minimal medium. Polysome levels return to normal if the sucrose-only spores are subsequently incubated in media which will support growth. Although germination can be initiated by the carbon source alone, other constituents are required for germ tube emergence and germ tube elongation. Magnesium deprivation leads to an inhibition and retardation in germ tube emergence, indicating that processes relating to formation of the germ tube require magnesium. Similarly, zinc deprivation leads to retardation in germ tube elongation, indicating that it is required for those processes involving germ tube elongation.