Synthesized and characterized nanoparticles-NPs (copper, copper oxide and copper doped zinc oxide) are exposed to host (Sesamum indicum L.; family: Pedaliaceae) for assessment of plant defense responses against oxidative stress with an objective to provide insight on stress minimizing reaction kinetics. The study also encompasses NPs accumulation in seedling ash in the form of cations using Atomic Absorption Spectroscopy (AAS). Results highlight the following: 1) Cu- and CuO-NPs exhibit non-coordinated antioxidant enzyme responsiveness by the host suggesting prevalence of cellular stress environment;while, Cu-doped ZnO-NPs show ground level reactivity and 2) antioxidant enzyme responses corroborates with NPs accumulation.