In Aspergillus nidulans, asexual development is inhibited by the conditions favorable for sexual differentiation, in which VeA is acting as a key regulator. Our previous proteomic analysis using VeA-deletion mutant revealed 13 proteins, VpdA ~ VpdL, of which expression level was affected by VeA. Although many of them affect various processes of fungal development, the deletion-effect of the VdpA, which has a SVF (survival factor)-like domain of yeast, was the most dramatic. In yeast, cells lacking SVF1 are defective in responding to the metabolic changes that occur during the diauxic shift and are hypersensitive to cold stress, H2O2 and menadione, conditions that elevate production of, or exposure to, reactive oxidative species. In contrast to the yeast, strains lacking the VdpA did not show any significant changes in response to oxidative stress. However, the VpdA-deletion strains showed reduced radial growth on solid medium and produced smaller mycelial balls with hyper-branching in liquid culture. The vegetative hyphae of the deletion mutants showed more frequent septation with narrow intervals. During asexual development, conidia-production was dramatically decreased mainly caused by abnormalities in conidiophore development including shortening of the conidiophore-stalk by vdpA-deletion. In sexual development, the vdpA-deletion mutants also showed a block of cleistothecial development at the primordial stage.
Full conference title:
Asian Mycological Congress 2013 and the 13th International Marine and Freshwater Mycology Symposium
- AMC 2013