Integrated Transcriptome and Proteome Analysis Reveals that the Antimicrobial Griseofulvin Targets Beta-Tubulin to Control Tea Leaf Spot.

Because effective control measures are lacking, tea leaf spot caused by results in huge tea () production losses on tea plantations in Guizhou Province, southwestern China. Screening for natural antimicrobial agents with higher control effects against this pathogen and studying their modes of action may contribute to disease management. Here, -derived antimicrobial griseofulvin (GSF) can inhibit the hyphal growth of strain GZSQ-4, with a half-maximal effective concentration of 0.37 μg/ml in vitro and a higher curative efficacy at a lower dose of 25 μg/ml for detached tea twigs. GSF induces deformed and slightly curly hyphae with enlarged ends, with protoplasts agglutinated in the hyphae, and higher numbers of hyphal protuberances. GSF alters hyphal morphology and the subcellular structure's order. The integrated transcriptome and proteome data revealed that the transport of materials in cells, cellular movement, and mitosis were modulated by GSF. Molecular docking indicated that beta-tubulin was the most potent target of GSF, with a binding free energy of -13.59 kcal/mol, and microscale thermophoresis indicated that the dissociation constant (Kd) value of GSF binding to beta-tubulin 1, compared with beta-tubulin 2, was significantly lower. Thus, GSF potentially targets beta-tubulin 1 to disturb the chromosomal separation and fungal mitosis, thereby inhibiting hyphal growth.