Abstract
The mechanism of fungitoxicity of higher alkylphenols upon mycelia of Piricularia oryzae, a pathogen of rice blast, was investigated comparing with the action of another phenolic fungicide, pentachlorophenol (PCP), and other chemicals.
Fungitoxicity of PCP was shown to be due to the uncoupling of oxidative phosphorylation in the fungous cells, but the uncoupling action of higher alkylphenols could not act as a primary factor of fungitoxicity. Higher alkylphenols inhibited uptake of glucose and glutamate into the cells, and removed ninhydrin-positive substances from the cells at and beyond the minimum growth-inhibitory concentration. This disturbance of the function of cell membrane may be caused by the absorption or distribution of a certain quantity of the phenol to the lipoidal layer of the cell membrane, and causes death of the fungi.
