Cu and CuO Nanoparticles Affected the Germination and the Growth of Barley (Hordeum vulgare L.) Seedling.

The application of Cu and CuO nanofertilizers in horticulture has been a promising strategy to promote plants' growth. In our study, increasing concentrations (10, 25, 50, 100, 250, 500, 1000, 2000 mg/L) were assessed for their inhibitory or stimulatory effects on barley (Hordeum vulgare L.) seedlings. Our results showed an enhancement of seed germination parameters (FGP, t50, cumulative germination rate, AUC), and seedling growth parameters (roots and shoots' lengths, fresh biomasses and dry biomasses) by the low concentrations of Cu NPs and CuO NPs, while concentrations above 500 mg/L displayed inhibiting effects. CuO NPs treatment showed a significant similitude with CuSO4, which confirms that CuO NPs act mainly via released Cu ions. However, Cu NPs exhibited a different behavior since the nanosized particles contribute together with Cu ions in barley response to Cu NPs. This provides an overall picture of the way these nanoparticles may behave in plant systems.