In vitro and in silico investigation of the antifungal activity of endophytic fungi against phytopathogenic fungi of tomato

Abstract

Plants are threatened by several diseases caused by phytopathogenic fungi. Melanin is an important pathogenicity factor in some fungal plant diseases. The enzyme 6,3,8-trihydroxynaphthalene reductase (3HNR) is implicated in the catalysis of the melanin biosynthesis in fungi. The chemical fungicide Phthalide acts by inhibiting this enzyme. But despite its efficacy, Phthalide can be detrimental to environmental health, hence the need to look for natural inhibitors to combat phytopathogenic fungi. This study aimed to screen the antifungal activity of some endophytic strains against phytopathogenic fungi of tomato. A total of 7 endophytic fungi were isolated and pre-identified from different parts of celery, parsley, mint, and coriander. On the other hand, five phytopathogenic fungal strains were isolated and pre-identified from tomatoes. The agar cylinder method showed that the endophytic fungi strains Fusarium and Trichoderma have significant inhibitory activity against four phytopathogenic fungi identified as Alternaria and Penicillium. Molecular docking was also used to study the inhibitory effect of some bioactive fungal compounds against the 3HNR enzyme. Drug-likeness and ADMET analyses were conducted on the selected chemicals to test their reliability and pharmaceutical efficacy. Phenylethyl alcohol interacts intensely with the binding site of the 3HNR receptor giving binding energy of -5.3 Kcal/mol, which is close to the co-crystallized ligand Phthalide. In addition, ADMET and pharmacokinetic analysis revealed that Phenylethyl alcohol verify the majority of the filters and pharmacokinetic properties necessary to select an effective antifungal molecule, including Lipinski’s and Veber’s rules.

Keywords

• 3HNR
• biological control
• endophytic microorganisms
• molecular docking
• phytopathogenic fungi