Exploring the impact of copper oxide nanoparticles on the biocontrol activity and plant growth promotion of Trichoderma asperellum

Agriculture is constantly in the search for new alternatives to control phytopathogens and improvement of plant growth. One of its main strategies is the use of biocontrollers, among them, Trichoderma genus stand out for their versatility and broad spectrum phytopatogenic fungi attacked. On the other hand, nanotechnology is positioning itself as an alternative to the use of agrochemicals, especially metal oxide nanoparticles, including ZnO, TiO₂ and CuO. Recently, it has been seen that when Trichoderma is put in contact with nanoparticles, it increases its biocontrol and biostimulant activity. Therefore, in this work we performed the characterization of a T. asperellum strain, which was capable to grow in different concentrations of CuO nanoparticles, obtaining that, at 200 ppm, Trichoderma showed no changes in growth and no apparent stress. Moreover, the strain developed a higher biocontrol activity against two Fusarium oxysporum strains, but decreases with F. fujikuroi, as well as changes in the expression of genes associated to biocontrol. Finally, an enhance in alfalfa growth is reported. These results suggest that, at the tested concentrations, CuO-NPs do not interfere with the biocontrol activity of T. asperellum, providing the basis for the development of a bionanoformulation to control F. oxysporum and promotes alfalfa growth.