Some aspects of germination induction in Phycomyces blakesleeanus by an ammonium-acetate pretreatment

Summary Dormancy in the sporangiospores of Phycomyces blakesleeanus can be broken by a short pretreatment (10 min at 30° C) with NH₄-acetate. The effect is partly reversible.Acetate activation is accompanied by a transient rise in trehalase activity, which causes a sharp decrease in the reserve substance trehalose followed by an accumulation of glucose in the surrounding medium. At the same time pyruvate, acetaldehyde, ethyl alcohol and lactate can be detected in the culture medium.CO₂ production by respiration of externally supplied glucose is predominant in dormant and in germinating spores. During acetate treatment most of the CO₂ produced, is supplied by the turnover of endogenous material.High activity of the pentose-phosphate (P-P) pathway occurs in dormant spores, as measured by the C₆/C₁ ratio. Adding acetate results in a sudden rise in the glycolytic Krebs cycle (EMP) pathway. Afterwards, the P-P pathway also increases and it predominates again during the initial phases of germination.