Author(s)

Janice Aparecida Rafael, Suraia Said

Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeir?o Preto, Universidade de S?o Paulo, S?o Paulo, Brazil.

Understanding the growth regulatory mechanisms in filamentous fungi is very important for the production of medicines for antifungal therapies. It is well established that Ca²⁺ gradient is essential for hyphal growth and that one mechanism responsible for the Ca²⁺ cellular concentration starts with the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP₂) by receptor-regulated forms of phosphoinositide-specific phospholipase C (PI-PLC). In the present study the levels of calcium in Aspergillus nidulans wild type (A26) and plcA-deficient mutant (AP27) growing in a carbon source readily assimilated, as glucose or pectin a non-readily assimilated carbon source was investigated. Intracellular calcium levels in A26 were higher in the presence of glucose than in pectin, but lower in AP27 independently of the carbon source and in AP27 the vesicular calcium distribution occurred mainly at the apex of the hyphae. Delay in nuclear division was also observed if A26 and AP27 were grown in pectin presence when compared with growth in glucose. For the first time, it is demonstrated that the levels of intracellular Ca²⁺ were higher when A. nidulans was growing in glucose than in a non readily assimilated carbon source as pectin. Further, it also showed that the plcA gene, although not essential, may be responsible for high-molecular weight carbon source recongnation, for the intracellular Ca²⁺ levels maintenance and consequently by the nuclear division in A. nidulans.

Aspergillus nidulans; Ca²⁺ Signaling; Phospholipase C

J. Aparecida Rafael and S. Said, "The Difference in Calcium Levels in Aspergillus nidulans Grown on Glucose or Pectin," Advances in Microbiology, Vol. 2 No. 2, 2012, pp. 117-121. doi: 10.4236/aim.2012.22016.