Aspergillus oryzae is ubiquitous filamentous fungi in nature and has been used in a number of industries such as Japanese traditional fermented foods and pharmaceutical products. In nature and industries, A. oryzae adapt to various environmental conditions by global change of transcriptional regulation. In the previous study, we revealed that the expression of histone acetylation related genes were affected by the growth phase and alteration of growing environment, such as culture conditions and stress exposing. In general, histone acetylation plays the fundamental roles for the genes expression, and closely relates to growth, morphology, differentiation and stress responses. Recently, several reports indicate that histone acetylation also plays important roles in filamentous fungi. In this context, we focused on histone acetylation related genes, particularly histone deacetylases (HDACs). We attempted to disrupt 11 HDACs homologue of A. oryzae and 10 of them were disrupted. However, in the deletion of RPD3 homologue, only the heterokaryon transformants had been isolated. This result suggests that RPD3 homologue is essential in A. oryzae. The phenotypes of 10 HDACs disruptants were observed in submerged and plate culture with/without several stress conditions. As the results, four disruptants showed considerable growth and developmental defects in these conditions, especially, HOS2 homologue null mutant showed significant decline of growth in submerged culture. In microscopic analysis, two disruptants showed abnormal hyphal branches and aberrant distribution of hyphae on the interface of medium and air. This study has indicated that HDACs play important roles in the growth and stress adaptation of A. oryzae.
Full conference title:
10th EUROPEAN CONFERENCE ON FUNGAL GENETICS
- ECFG 10th (2010)