A Putative NADPH Oxidase Gene in Unicellular Pathogenic Is Required for Fungal ROS Production and Oxidative Stress Response.

Most previous studies on fungal NADPH oxidases (Nox) focused on multicellular fungi and highlighted the important roles of Nox-derived reactive oxygen species (ROS) in cellular differentiation and signaling communication. However, there are few reports about Nox in unicellular fungi. A novel ortholog, (named ), in was investigated in this study. Deletion of led to a decrease in both intracellular and extracellular ROS production. In addition, the mutant exhibited hypersensitivity to hydrogen peroxide and menadione. Also, the wild-type strain showed higher levels of both mRNA expression and ROS production under oxidative stress. Moreover, the absence of resulted in impaired ferric reductase activity. Although there was no effect on in vitro biofilm formation, the mutant did not produce hepatic apoptosis, which might be mediated by fungal Nox-derived ROS during co-incubation. Together, these results indicated that the novel gene plays important roles in unicellular pathogenic and its interaction with host cells.