EFFECTS OF HEAT-SHOCK ON THE LEVEL OF TREHALOSE AND GLYCOGEN, AND ON THE INDUCTION OF THERMOTOLERANCE IN NEUROSPORA-CRASSA

Neurospora crassa conidiospore germlings exposed to a heat shock (30-45-degrees-C) rapidly accumulated trehalose and degraded glycogen, even in the presence of cycloheximide. This phenomenon was also rapidly reversible upon return of the cells at 30-degrees-C. Trehalose accumulation at 45-degrees-C demanded an exogenous source of carbon and either glucose or glycerol fulfilled such requirement. Experiments with the cyclic AMP-deficient cr-l mutant suggested that the effects of temperature shifts on trehalose level were independent of cAMP metabolism. Cells exposed at 45-degrees-C under conditions permissive for trehalose accumulation (i.e. in the presence of an assimilable carbon source) also acquired thermotolerance.