Inhibitory Effect and Mechanism of Dryocrassin ABBA Against Fusarium oxysporum

Potato <i>Fusarium</i> dry rot and wilt are the most important soil- and seed-borne diseases in potatoes. They cause high economic losses during potato growth and storage across the world. Previous observations have shown that dryocrassin ABBA can induce resistance in potatoes. However, little is known about whether dryocrassin ABBA can suppress <i>Fusarium oxysporum</i>. In this research, we determined that exogenous dryocrassin ABBA significantly inhibited the mycelial growth, changed the cell ultrastructure, increased the MDA content, and decreased the antioxidant enzyme activity of <i>F. oxysporum</i>. The transcriptome analysis of <i>F. oxysporum</i> with or without dryocrassin ABBA indicated that 1244 differentially expressed genes (DEGs) were identified, of which 594 were upregulated and 650 were downregulated. GO term analysis showed that the DEGs were mostly related to biological processes. The KEGG pathway was mainly related to carbohydrate, amino acid, and lipid metabolism. Moreover, most of the expressions of PCWDEs, HSPs, and MFS were downregulated, decreasing the stress capacity and weakening the pathogenicity of <i>F. oxysporum</i> with dryocrassin ABBA treatment. These findings contribute to a new understanding of the direct functions of dryocrassin ABBA on <i>F. oxysporum</i> and provide a potential ecofriendly biocontrol approach for potato <i>Fusarium</i> dry rot and wilt.