Magnolol inhibits Colletotrichum gloeosporioides via disruption of plasma membrane and induction of reactive oxygen species accumulation

Abstract

Colletotrichum gloeosporioides caused anthracnose in various tropical fruit, resulting in substantial agricultural loss. Anthracnose diseases are mainly managed by chemical fungicides, which excessive use has led to resistant pathogens and concerns about food safety. In this study, magnolol, a plant-derived active compound from Magnolia officinalis, was investigated. In vivo experiments demonstrated that 4 g L−1 magnolol significantly retarded the expansion of anthracnose lesions in mango fruit. Significant inhibition of C. gloeosporioides growth was observed at magnolol concentration higher than 20 mg L−1, with MIC and IC50 values of 55.98 and 31.0 mg L−1 for mycelial growth, 345.68 and 82.37 mg L−1 for spore germination, respectively. The inhibitory effect was primarily attributed to the disruption of plasma membrane integrity, which led to the leakage of ion, macromolecules, nucleic acids and proteins. Furthermore, magnolol induced the accumulation of reactive oxygen species (ROS), resulting in oxidative stress that perturb cellular functions and even induce cell death. Therefore, magnolol has potential as a feasible substitute for controlling anthracnose.