摘要：The recent emerging evidence reveals that titanium dioxide nanoparticles (TiO<sub>2</sub> NPs) can be used as a wastewater treatment. This study provides new information about the possible detoxification role of TiO<sub>2</sub> NPs as a wastewater treatment in plants under heavy metal stress, with an emphasis on the mechanisms involved. Here, we investigated the effects of TiO<sub>2</sub> NPs as one wastewater treatment on a bamboo species (<i>Arundinaria pygmaea</i> L.) under in vitro Cadmium (Cd) toxicity conditions. A factorial experiment was conducted in a completely randomized design with four replications of four concentrations of Cd (50, 100, 200, and 300 µM) alone and in combination with 100 and 200 µM TiO<sub>2</sub> NPs as two wastewater treatments, as well as a control treatment. The results indicated that TiO<sub>2</sub> NPs concentrations enhanced enzymatic and non-enzymatic antioxidant activities and proline accumulation as well as reducing hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), superoxide radical (O<sub>2</sub><sup>•−</sup>), and malondialdehyde (MDA) levels, which led to improved photosynthetic parameters with an eventual increase in plant biomass as compared to the control treatment. Therefore, TiO<sub>2</sub> NPs improved the photosynthetic parameters of bamboo under Cd toxicity, which led to an increase in plant biomass. We concluded that the wastewater treatments of TiO<sub>2</sub> NPs improved bamboo biomass through the scavenging of reactive oxygen species (ROS) compounds (H<sub>2</sub>O<sub>2</sub> and O<sub>2</sub><sup>•−</sup>), which was induced by the stimulation of the antioxidant capacity of the plant. TiO<sub>2</sub> also protected cell membranes by reducing lipoperoxidation in bamboo under Cd toxicity. The concentration of 200 µM TiO<sub>2</sub> NPs had the most impact in reducing Cd toxicity.
