Glucose metabolism of dormant and heat-activated spores of Phycomyces blakesleeanus burgeff

Abstract

The metabolism of [(14)C]glucose has been studied in Phycomyces spores during dormancy, activation, and the initial stages of germination. Dormant spores are able to take up and metabolize exogenous glucose into different products; the major part of it goes to trehalose synthesis (up to 60% when the external glucose concentration exceeds 10(-3) M). During activation itself (i.e. a prolonged treatment at 50°) there is a general increase of glucose uptake and metabolism, without major changes in the relative rates of (14)C-label distribution in the different fractions (as compared to the metabolism of dormant spores), except for a drop in material insoluble in 80% ethanol and a still higher percentage (73%) going to trehalose synthesis. In the early hours of germination we find an enhancement of the uptake and metabolism of glucose. Trehalose synthesis is practically switched off within 2 h whereas the major part of glucose (65%) is metabolized to CO2 and ethanol-insoluble proteinaceous material.