Redox Imbalance at the Start of Each Morphogenetic Step of Neurospora crassa Conidiation

The conidiation process of Neurospora crassa is characterized by three morphogenetic steps: hyphal adhesion, aerial hyphal formation, and production of conidia. Total protein oxidation and specific enzyme oxidation coincided with an increased oxygen-dependent chemiluminescence and indicated the occurrence of a hyperoxidant state at the onset of all three morphogenetic steps. Oxidation of NAD(P)H and excretion of glutathione disulfide was detected at the start of hyphae adhesion. Here we show that NAD(P)H and glutathione redox imbalance also occurred at the beginning of aerial hyphal growth and just before formation of conidia in the isolated cell structures. An increased loss and oxidation of NAD(P)(H) and glutathione were detected with each morphogenetic transition. These results give further support to our proposal that a hyperoxidant state develops at the start of each of the three morphogenetic processes during N. crassa conidiation.