Benzimidazole Derivatives Suppress Fusarium Wilt Disease via Interaction with ERG6 of Fusarium equiseti and Activation of the Antioxidant Defense System of Pepper Plants.

Sweet pepper ( L.), also known as bell pepper, is one of the most widely grown vegetable crops worldwide. It is attacked by numerous phytopathogenic fungi, such as , the causal agent of Fusarium wilt disease. In the current study, we proposed two benzimidazole derivatives, including 2-(2-hydroxyphenyl)-1-H benzimidazole (HPBI) and its aluminum complex (Al-HPBI complex), as potential control alternatives to . Our findings showed that both compounds demonstrated dose-dependent antifungal activity against in vitro and significantly suppressed disease development in pepper plants under greenhouse conditions. According to in silico analysis, the genome possesses a predicted Sterol 24-C-methyltransferase () protein that shares a high degree of homology with from (). It is worth mentioning that molecular docking analysis confirmed that both compounds can interact with from as well as from Moreover, root application of HPBI and its aluminum complex significantly enhanced the enzymatic activities of guaiacol-dependent peroxidases (POX), polyphenol oxidase (PPO), and upregulated four antioxidant-related enzymes, including superoxide dismutase [Cu-Zn] (), L-ascorbate peroxidase 1, cytosolic (), glutathione reductase, chloroplastic (), and monodehydroascorbate reductase (). Additionally, both benzimidazole derivatives induced the accumulation of total soluble phenolics and total soluble flavonoids. Collectively, these findings suggest that the application of HPBI and Al-HPBI complex induce both enzymatic and nonenzymatic antioxidant defense machinery.