Mycogenic Copper Oxide Nanoparticles For Fungal Infection Management in Agricultural Crop Plants

Abstract

Aspergillus infections are one of the significant threats to crop plants such as peanuts, cottonseed, maize, tree nuts, food, and feed. The fungal members of this genus can cause up to 100% losses in fruit plants under favorable conditions. It is thus a necessity to control these phytopathogenic fungi by a renewable, non-hazardous technology. Phoma spp. are well known to synthesize antifungal metabolites like 4,8-dihydroxy-6-methoxy-3-methyl-3,4-dihydro-1H-isochromen-1-one, Viridicatol, tenuazonic acid, alternariol, alternariol monomethyl ether, phomafungin, etc. In the present work, copper oxide nanoparticles (CuONPs) were synthesized using an aqueous extract of Phoma glomerata (MTCC-2210). They were assessed for in vitro antifungal activity against Aspergillus flavus and Aspergillus niger. CuONPs showed absorption maxima at 630 nm and an average size of 119.6 nm, which were stable at a zeta potential of -23.5 mV, forming the face-centered cubic (FCC) shaped crystalline structure as elucidated by XRD. FTIR confirmed the presence of various secondary metabolites from fungal extracts in the NPs capping. Kirby-Bauer disc diffusion assay indicated the antifungal activity with an average zone of inhibition of 19 +3 mm and 23 +4 mm diameter for A. niger and A. flavus, respectively. The serial dilution method 2 showed the MIC of 180 and 220 μg/ml against A. niger and A. flavus, respectively. MIC values were significantly compared to standard fungicide mancozeb. Green synthesized CuONPs using Phoma extract indicated significant fungicidal activity against test pathogens and paved their way to be applied in the agriculture fields for crop applications as a novel substitute to chemical fungicides.