Role of phospholipase C and protein kinase C in Aspergillus nidulans during growth on pectin or glucose: Effects on germination and duplication cycle.

The effects of PLC and Pkc inhibitors on Aspergillus nidulans depend on the carbon source. PLC inhibitors Spm and C48/80 delayed the first nuclear division in cultures growing on glucose, but stimulated it in media supplemented with pectin. Less intense were these effects on the mutant transformed with PLC-A gene rupture (AP27). Neomycin also delayed the germination in cultures growing on glucose or pectin; however, on glucose, the nuclear division was inhibited whereas in pectin it was stimulated. These effects were minor in AP27. The effects of Ro-31-8425 and BIM (both Pkc inhibitors) were also opposite for cultures growing on glucose or pectin. On glucose cultures of both strains BIM delayed germination and the first nuclear division, whereas on pectin both parameters were stimulated. Opposite effects were also detected when the cultures were growing on glucose or pectin in the presence of Ro-31-8425.

Germination, duplication cycle and septum formation are altered by caffeine, caffeic acid and cinnamic acid in Aspergillus nidulans.

Phenolic and benzene compounds from vegetables have been described as being responsible for many biological activities including antifungal effects. Caffeine, cinnamic and caffeic acids were here investigated for their action on a model fungus, Aspergillus nidulans, at its initial stage of germination. Conidia did not germinate in the presence of (1 mM) cinnamic acid. Caffeine and caffeic acid exerted a negative effect on germination, on the nuclear duplication cycle and on first septum formation. The effects of caffeine were dose-dependent; effects of (1 mM) caffeic acid were more intense than those of (10 mM) caffeine.