Mechanistic insights into the activity of a plant-based compound against Alternaria solani

Early blight, caused by the fungal pathogen Alternaria solani , is one of the most destructive diseases of tomato, resulting in severe yield losses worldwide. Here, we show that CC2020, a plant-based formulation enriched with savory essential oil, exhibits potent antifungal activity against A. solani through multiple complementary mechanisms. Under in vitro conditions, treatment with CC2020 at a concentration of 300 ppm effectively suppressed the effector gene expression AsCEP50 and downregulated the melanin-biosynthesis gene pks , both of which are essential determinants of fungal virulence. Furthermore, treatment markedly increased intracellular glutathione (GSH) levels, indicating activation of the fungi’s antioxidant defense machinery. Collectively, these findings demonstrate the high efficacy of CC2020 and establish it as a sustainable, eco-friendly, and potent bioformulation for early blight management. This work underscores the potential of plant-derived formulations as effective, sustainable, and environmentally responsible components of integrated disease management strategies in crops.