Equol, a Clinically Important Metabolite, Inhibits the Development and Pathogenicity of Magnaporthe oryzae, the Causal Agent of Rice Blast Disease

Abstract

Equol, a metabolite of soybean isoflavone daidzein, has been proven to have various bioactivities related to human health, but little is known on its antifungal activity to plant fungal pathogens. <i>Magnaporthe oryzae</i> is a phytopathogenic fungus that causes rice blast, a devastating disease on rice. Here, we demonstrated that equol influences the development and pathogenicity of <i>M. oryzae</i>. Equol showed a significant inhibition to the mycelial growth, conidial generation and germination, and appressorial formation of <i>M. oryzae</i>. As a result, equol greatly reduced the virulence of <i>M. oryzae</i> on rice and barley leaves. The antifungal activity of equol was also found in several other plant fungal pathogens. These findings expand our knowledge on the bioactivities of equol.