Mechanistic Insight of the Antifungal Potential of Green Synthesized Zinc Oxide Nanoparticles against Alternaria brassicae

Abstract

Alternaria brassicae is a necrotrophic fungus causes Alternaria blight disease in oilseed mustard crop. There is a 47% loss of the mustard crop due to the Alternaria blight disease. To control this disease, various chemical fungicides have been used till date which are harmful to our environment. Zinc oxide (ZnO) nanoparticles synthesized from Terminalia bellerica have been reported to have significant antifungal potential against A. brassicae at 200 ppm concentration. In the present study, the effect of green synthesized zinc oxide (Tb-ZnO) nanoparticles, chemically synthesized ZnO nanoparticles, and chemical fungicides on A. brassicae has been anticipated by analysing changes in cytomorphology characteristics, biochemical constituent, and stress enzymes of A. brassicae. Cytomorphological studies by transmission electron microscopy and scanning electron microscopy have shown the complete disintegration of cell wall, cell membrane, and cytoplasmic content at 200 ppm concentration of Tb-ZnO nanoparticles. Decrement in biochemical constituents and changes in activity of stress enzymes in Tb-ZnO nanoparticles treated cell confirm the toxicity of nanoparticles at 200 ppm concentrations. Hence, on the basis of all these results, the mechanism of action of Tb-ZnO nanofungicides on A. brassicae has been hypothesized in the present study. This study confirms how nanoparticles inhibit the growth of A. brassicae and suggested the use of nanofungicides.