The major component of cinnamon oil as a natural substitute against Fusarium solani on Astragalus membranaceus

Abstract

Abstract Aims Root rot caused by Fusarium solani is an important disease seriously affecting the yield and quality of Astragalus membranaceus. Therefore, this study was performed to elucidate the antifungal activities and mechanisms of cinnamaldehyde treatment against F. solani and its control effect for A. membranaceus root rot. Methods and Results Cinnamaldehyde significantly inhibited mycelial growth and spore germination of F. solani in dose-dependent, and the median effective concentration was 178.68 μl l−1. Furthermore, scanning electron microscopy, propidium iodide staining, cell leakage experiments and ergosterol quantitation illuminated that cinnamaldehyde could alter the mycelial morphology, damage the plasma membrane and hinder the biosynthesis of ergosterol. Besides, cinnamaldehyde induced the generation of reactive oxygen species by synergistically upregulating the genes encoded subunits for NADPH oxidase. The disease suppression efficacy of 600 μl l−1 cinnamaldehyde against A. membranaceus root rot was 92.98 ± 6.08% (p < 0.05) under greenhouse conditions. Conclusions This study proved that cinnamaldehyde could markedly inhibit the growth of F. solani in vitro and effectively suppress the occurrence of A. membranaceus root rot, perhaps by inducing oxidative damage, which results in the distortion of F. solani, and the destruction of cell membrane integrity and permeability. Significance and Impact of the Study This study first explores the antifungal mechanisms of cinnamaldehyde against F. solani in vivo and vitro, thereby providing a promising candidate for disease biocontrol.