Efficient Control\nof Fusarium Head Blight and Reduction\nof Deoxynivalenol Accumulation by a Novel\nNanopartner-Based Strategy

Chemical control of <i>Fusarium</i> head blight\n(FHB)\nin wheat plants is often challenged by the resistance outbreak and\ndeoxynivalenol (DON) accumulation. Developing green partners for fungicides\nis crucial for reducing fungal growth, mycotoxin contamination, and\nagricultural fungicides input. Herein, we investigated the mechanism\nof MgO nanoparticles (NPs) in controlling FHB. The EC<sub>50</sub> of MgO NPs on mycelial growth was 105.2 μg/mL. At this concentration,\nthey inhibited the spore germination, DON production, and wheat colonization\nof Fusarium graminearum by 56.0%, 24.5%,\nand 43.8%, respectively, exhibiting superior performance compared\nto nine other bioactive NPs such as ZnO and TiO<sub>2</sub>. Importantly,\nMgO NPs showed an additive effect with carbendazim and azoxystrobin\nin inhibiting F. graminearum. The extracellular\ntoxicity of MgO NPs against F. graminearum was mainly attributed to the inhibition of fungal growth and germination\nby oxidative damage, alkaline damage, and cell structure damage. Although\nMgO NPs could not be absorbed into mycelia, they (EC<sub>90</sub>)\ndecreased the soluble protein content and DNA concentration of mycelia\nby 27.8% and 42.3%, respectively, and increased the pyruvate content\nby 67.4%, demonstrating that the intracellular toxicity was mainly\nbased on their inhibition of protein and DNA production and promotion\nof carbohydrate degradation. With low risks to nontarget organisms,\nMgO NPs could be a promising nanopartner for fungicides to protect\nwheat from FHB and mitigate fungicide overuse.