Dynamic changes in membrane permeability, nitro-oxidative stress and mycotoxin production of Fusarium spp. due to antifungal activity of Scutellaria luteocaerulea

Dichloromethane extract (DCM) of Scutellaria luteocaerulea root has inhibitory effect against Fusarium culmorum and Fusarium pseudograminearum. This DCM fraction caused cell membrane damage in the hyphal cells of Fusarium spp. and decreased fungal biomass. The fraction induced apoptosis in hyphal cells of both pathogens via increasing accumulation of hydrogen peroxide (H2O2), hydroxyl radicals (.OH), and nitrogen dioxide (NO2). The DCM fraction reduced antioxidant activity in both pathogens. Application of the DCM fraction via seed treatment and wheat head spraying reduced the disease severity, deoxynivalenol (DON) accumulation, and expression of the tri5 gene in both fungi causing Fusarium head blight (FHB). The High Performance Liquid Chromatography (HPLC) method was used to separate microfractions of the DCM fraction, and thirty microfractions were obtained. Similar microfractions were combined using thin-layer chromatography (TLC) and 8 microfractions were created. These microfractions were assessed for antifungal activity at 100 μg mL−1 concentration in vitro. Among them, F5 microfraction showed the best antifungal effect against both pathogens. Also, an analytical method based on the liquid chromatography-mass spectrometry (LC-MS) analysis was used to identify secondary metabolites of the F5 microfraction. Therefore, the DCM fraction of S. luteocaerulea might be used for plant protection against FHB disease.