Vernicia fordii leaf extract inhibited anthracnose growth by downregulating reactive oxygen species (ROS) levels in vitro and in vivo

is a predominant anthracnose species in , causing various adverse effects. Traditional intercropping with may enhance anthracnose resistance, but the mechanism remains elusive. We utilized UPLC-MS/MS and acid-base detection to identify the major antimicrobial alkaloid components in the leaf extract. Subsequently, by adding different concentrations of leaf extract for cultivating , with untreated as a control, we investigated the impact of the leaf extract, cell wall integrity, cell membrane permeability, MDA, and ROS content changes. Additionally, analysis of key pathogenic genes of confirmed that the leaf extract inhibits the growth of the fungus through gene regulation. This study discovered the alkaloid composition of leaf extract by UPLC-MS/MS and acid-base detection, such as trigonelline, stachydrine, betaine, and O-Phosphocholine. leaf extract successfully penetrated mycelia, damaged cellular integrity, and increased ROS and MDA levels by 1.75 and 2.05 times respectively, thereby inhibiting proliferation. By analyzing the key pathogenic genes of , it was demonstrated that the antifungal function of leaf extract depends mainly on the regulation of and gene expression. Therefore, this study elucidates the mechanism of - intercropping in strengthening anthracnose resistance in , contributing to efficient cultivation.