XXXX , a Fungal Self-Inhibitor, Prevents Germination of Rhizopus oligosporus Sporangiospores by Dissipation of the pH Gradient.

@entity6212 @entity12312 @entity12311 @entity1718 @entity27145 @entity59748 @entity1543
Germination of Rhizopus oligosporus sporangiospores is characterized by swelling of the spores and subsequent emergence of germ tubes. Changes in spore morphology and alterations in intracellular pH (pH(infin)) of the sporangiospores were assessed during the germination process by flow cytometry. Sporangiospores were stained with @entity12311 by incubation with @entity12312 . The nonfluorescent @entity12312 is passively transported into intact cells and subsequently cleaved by esterases, which results in intracellular accumulation of the fluorescent @entity12311 . Given that the fluorescence of @entity12311 is pH dependent, the pH(infin) of the individual spores could be assessed simultaneously with spore size. For R. oligosporus, swelling of the sporangiospores was accompanied by an increase of pH(infin). In the presence of @entity59748 , a self-inhibitor produced by various fungi, increase of the pH(infin) was prevented and swelling was inhibited at concentrations of less than 1 mM. @entity6212 and @entity27145 were equally effective. @entity1543 also inhibited germination but at much higher concentrations (>8 mM). The mechanism of action of these @entity1718 is most likely dissipation of the pH gradient. A model is proposed in which the pH(infin) plays a crucial role in the germination of R. oligosporus sporangiospores.
