Genetic analysis of conidiation regulatory pathways in koji-mold Aspergillus oryzae.
Conidia of koji-mold Aspergillus oryzae are often used as starters in the fermented food industry. However, little is known about conidiation regulation in A. oryzae. To improve the productivity of conidia in A. oryzae, it is necessary to understand conidiation regulation in the strain. Therefore, we analyzed the conidiation regulatory system in A. oryzae using 10 kinds of conidiation regulatory gene disruptants. The phenotypes of AorfluG, AorflbA, AorflbB, AorflbC, AorflbD, AorflbE, AorbrlA, AorabaA, AorwetA, and AorfadA mutants are almost identical to those of the corresponding mutants in Aspergillus nidulans. The results indicated that the functions of conidiation regulatory genes are almost conserved between A. oryzae and A. nidulans. However, the severely reduced conidiation phenotype of the AorfluG disruptant in A. oryzae differs from the phenotype of the corresponding mutant in Aspergillus fumigatus in air-exposed culture conditions. These results suggest that A. oryzae, A. nidulans, and A. fumigatus have a G-protein signaling pathway and brlA orthologs in common, and only A. fumigatus has particular brlA activation pathways that are independent of the fluG ortholog. Furthermore, the analyses of AorflbA disruptant and AorfadA dominant-active mutants implicated that AorFadA-mediated G-protein signaling suppresses vegetative growth of A. oryzae.
Ogawa
Masahiro
M
Noda Institute for Scientific Research, Noda City, Chiba 278-0037, Japan. maogawa@mail.kikkoman.co.jp
Tokuoka
Masafumi
M
Jin
Feng Jie
FJ
Takahashi
Tadashi
T
Koyama
Yasuji
Y
D001236:Aspergillus oryzae / Q000235:genetics* / Q000254:growth & development; D019204:GTP-Binding Proteins / Q000235:genetics; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D005810:Multigene Family; D015398:Signal Transduction; D013172:Spores, Fungal / Q000235:genetics* / Q000254:growth & development
D019204:GTP-Binding Proteins