Abstract

To know the function of the plcA gene, which encodes a putative phosphoinositide-specific phospholipase C, in a model filamentous fungus Aspergillus nidulans, it was disrupted thorough homologous recombination and examined. The germination rate of ΔplcA was reduced by approximately 65% and germination of ΔplcA at a lower temperature (25°C) was much slower than germination under normal conditions (37°C), suggesting the plcA is responsible for cold-sensitivity. The hyphal growth of ΔplcA was slightly reduced at 37°C and conspicuously reduced at 25°C. While germinating ΔplcA formed giant swollen spores, and generated short and thick hyphae. The results of the nuclear examination of ΔplcA showed nuclear division with missegregation, and the rate of nuclear division was lower than that of wild type at both 25°C and 37°C. The results of this study showed that plcA is localized to the nucleus through intracellular calcium signaling in A. nidulans. The abnormal nuclear division, resulting from plcA gene deletion, affects conidiation in asexual development. Taken together, these results suggested that plcA is required for normal vegetative growth, morphogenesis, conidiation, and nuclear division
in A. nidulans.

• Keywords: Aspergillus nidulans; PlcA; germination; conidiation; nuclear division; nuclear translocation