Antifungal Effect of Copper Nanoparticles against Fusarium kuroshium, an Obligate Symbiont of Euwallacea kuroshio Ambrosia Beetle

Abstract

Copper nanoparticles (Cu-NPs) have shown great antifungal activity against phytopathogenic fungi, making them a promising and affordable alternative to conventional fungicides. In this study, we evaluated the antifungal activity of Cu-NPs against Fusarium kuroshium, the causal agent of Fusarium dieback, and this might be the first study to do so. The Cu-NPs (at different concentrations) inhibited more than 80% of F. kuroshium growth and were even more efficient than a commercial fungicide used as a positive control (cupric hydroxide). Electron microscopy studies revealed dramatic damage caused by Cu-NPs, mainly in the hyphae surface and in the characteristic form of macroconidia. This damage was visible only 3 days post inoculation with used treatments. At a molecular level, the RNA-seq study suggested that this growth inhibition and colony morphology changes are a result of a reduced ergosterol biosynthesis caused by free cytosolic copper ions. Furthermore, transcriptional responses also revealed that the low- and high-affinity copper transporter modulation and the endosomal sorting complex required for transport (ESCRT) are only a few of the distinct detoxification mechanisms that, in its conjunction, F. kuroshium uses to counteract the toxicity caused by the reduced copper ion.

Green synthesis of CuO nanoparticles using Ligustrum lucidum extract, and the antioxidant and antifungal evaluation

“…The pooled mycelium inhibition was higher at 1 ppm, compared to 0.5 ppm for the fungal species. This was similar to the result reported by [45] for F. oxysporum mycelium inhibition by CuO-NPs. At both studied concentrations the pooled effect was highest for A. niger.…”

“…The combination of several parameters, including duration of exposure, humidity, and temperature, determines the toxicity of CuO-NPs [43]. According to reports, copper interacts with microorganisms through a variety of mechanisms, including denaturation of nucleic acids, protein modification, membrane lipid peroxidation, and cell membrane permeabilization, all of which can result in cell death [44,45]. The antifungal efficacy in this study revealed the potential ability of CuO-NPs to provide a surface for killing fungal strain with extensive cell membrane damage through cell vacuole enlargement and disappearance [46,47].…”

Insights into Ag-NPs-mediated pathophysiology and ultrastructural aberrations in ovarian tissues of darkling beetles

“…A recent report revealed the antifungal competency of copper nanoparticles (Cu-NPs) against Fusarium kuroshium , manifesting the significant enrichment of the oxidation–reduction processes and enzymes with oxidoreductase activity. Moreover, F. kuroshium attempted to hinder the shuttle and interactions of Cu + with some organelles, such as Golgi bodies and the mitochondria 39 . Another study reported the capacity of magnesium oxide nanoparticles (Mg-NPs) to thwart the growth of Gram-negative and Gram-positive bacteria by generating high amounts of ROS as a dominant mechanism.…”

Potential Antifungal Effect of Copper Oxide Nanoparticles Combined with Fungicides against Botrytis cinerea and Fusarium oxysporum

“…Among metals, copper is a recognized broad-spectrum antimicrobial agent usually present in agrochemical products. Currently, the formulation of copper and copper oxide nanoparticles (NCuO) is the focus of many studies due to their reported better antimicrobial effect than copper salts [ 10 , 11 , 12 ]. Also, NCuO share similar antimicrobial activity to other noble metals such as silver and gold; however, they are considered cost-effective due to their cheaper and easier production and their more abundant presence in nature [ 13 , 14 ].…”