MgO and Zn/MgO Nanoparticles as Direct Antifungal Compounds and Elicitors Against Sclerotinia sclerotiorum in Pea

The purpose of this study was to assess the effectiveness of two nanostructures (MgO and Zn/MgO) against Sclerotinia sclerotiorum, which causes white mold disease in peas, as direct antifungal agents or resistance inducers in pea plants. The direct antifungal activity of these nanostructures was evaluated by assessing their ability to inhibit S. sclerotiorum growth in vitro and reduce white mold severity in the greenhouse. The induction of resistance in pea plants was examined by assessing the expression of three defense-related genes using quantitative real-time PCR and measuring the phenolic compounds content in treated pea plants relative to untreated controls. The effect of the tested control agents on the growth and yield of pea plants was investigated. In comparison to the untreated control, S. sclerotiorum growth was markedly suppressed following treatment with the investigated compounds. The complete suppression (100%) of S. sclerotiorum growth was achieved with concentration levels of 100 mg/L for both MgO and Zn/MgO nanostructures. In greenhouse conditions, pea plants treated with the investigated chemicals showed a considerable reduction in the severity of white mold disease when compared to the untreated control plants. The transcript levels of 12-oxophytodienoate reductase 11 (OPR1), antioxidant peroxide (PsOXII), and chlorophyll a-b binding protein genes increased significantly in treated plants with MgO (3.1, 2.7, and 3.5-fold), fungicide (3.2, 2.8, and 2.8-fold), and Zn/MgO (3.5, 3, and 5-fold) compared to control, respectively. Pea plants treated with the tested nanoparticles generated more phenolic content than untreated controls. The application of fungicide and tested nanoparticles to peas greatly enhanced their growth properties. In light of our results, the application of these nanoparticles may represent a novel approach for controlling this pathogen.