Antifungal activity and potential mechanism of paeonol against Fusarium graminearum and the application on wheat grains and steamed bread

Abstract

Fusarium graminearum (F. graminearum) is a severe phytopathogen threatening agriculture production and food security. Paeonol, serves as a plant-derived natural component, is a promising antifungal agent. At a concentration of 0.3125 mg/mL, paeonol was adequate to fully inhibit the growth of F. graminearum mycelia within 3 days. Fourier-Transform Infrared Spectroscopy (FT-IR) analysis showed that paeonol had no impact on the outer surface of F. graminearum cell walls. While propidium iodide staining, extracellular conductivity, and pH value measurements demonstrated that paeonol disrupted the cell membrane. Furthermore, lipid oxidation and osmotic stress responses were observed in F. graminearum treated with paeonol, resulting in a 47.23% rise in malondialdehyde (MDA) levels and a 515.43% increase in glycerol levels. Moreover, on the 7th day after exposure to paeonol treatment, the deoxynivalenol (DON) level was significantly reduced, measuring only one-fifth of that in the control group. Finally, paeonol was shown to inhibit F. graminearum on wheat grains and steamed bread slices. These results, for the first time, revealed the inhibitory mode of action of paeonol against F. graminearum as reflected by disruption of cell membrane integrity, induction of lipid oxidation and osmotic pressure, as well as DON biosynthesis. Furthermore, this study provided scientific evidence for the potential applications of paeonol in agriculture and food industry.