The Investigation of TiO2 NPs Effect as a Wastewater Treatment to Mitigate Cd Negative Impact on Bamboo Growth

Abstract

The recent emerging evidence reveals that titanium dioxide nanoparticles (TiO2 NPs) can be used as a wastewater treatment. This study provides new information about the possible detoxification role of TiO2 NPs as a wastewater treatment in plants under heavy metal stress, with an emphasis on the mechanisms involved. Here, we investigated the effects of TiO2 NPs as one wastewater treatment on a bamboo species (Arundinaria pygmaea 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 TiO2 NPs as two wastewater treatments, as well as a control treatment. The results indicated that TiO2 NPs concentrations enhanced enzymatic and non-enzymatic antioxidant activities and proline accumulation as well as reducing hydrogen peroxide (H2O2), superoxide radical (O2•−), and malondialdehyde (MDA) levels, which led to improved photosynthetic parameters with an eventual increase in plant biomass as compared to the control treatment. Therefore, TiO2 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 TiO2 NPs improved bamboo biomass through the scavenging of reactive oxygen species (ROS) compounds (H2O2 and O2•−), which was induced by the stimulation of the antioxidant capacity of the plant. TiO2 also protected cell membranes by reducing lipoperoxidation in bamboo under Cd toxicity. The concentration of 200 µM TiO2 NPs had the most impact in reducing Cd toxicity.

Co-Application of 24-Epibrassinolide and Titanium Oxide Nanoparticles Promotes Pleioblastus pygmaeus Plant Tolerance to Cu and Cd Toxicity by Increasing Antioxidant Activity and Photosynthetic Capacity and Reducing Heavy Metal Accumulation and Translocation

“…The impact of TiO 2 NPs on increasing antioxidant activity and plant growth has been reported in several studies [13,14,46]. This increase can be attributed to the inductive role of TiO 2 NPs in enhancing signaling associated with the activation of antioxidant enzyme activity [13]. This finding is consistent with the reported results in the present study.…”

“…Titanium, as a form of TiO 2 , has the ability to alter the bioavailability and behavior of metals in the environment [45]. The impact of TiO 2 NPs on increasing antioxidant activity and plant growth has been reported in several studies [13,14,46]. This increase can be attributed to the inductive role of TiO 2 NPs in enhancing signaling associated with the activation of antioxidant enzyme activity [13].…”

“…Titanium nanoparticles were provided by Nanjing Jiancheng Company, Jiangsu Province, China, and consisted of a white powder with a purity of >99% nanotitanium and a diameter of 25 nm. The levels of Cu and Cd were chosen according to the previous studies, which displayed high and low levels of toxicity in bamboo plants [13,14]. Bamboo (A. pygmaeus) was selected from local species by the Bamboo Research Institute, which is located at Nanjing Forestry University.…”

“…The diverse surface-to-volume ratios of nanoparticles could differ from their bulk counterparts [12]. Recently, some studies have reported that titanium nanoparticles (TiO 2 ) have the ability to increase plant growth under metal stress [13][14][15][16][17]. Therefore, we suggest that titanium could be a good material to reduce plant stress.…”

Zinc Oxide Nanoparticles Improve Pleioblastus pygmaeus Plant Tolerance to Arsenic and Mercury by Stimulating Antioxidant Defense and Reducing the Metal Accumulation and Translocation

“…It has high tolerance to grow in basic (alkaline), acidic, and neutral soils throughout the year ( Huang et al, 2020b ) and is cultivated in many areas and provinces in China such as Jiangsu province. On the other hand, HMs are one of the important toxic factors in water and soil in the Southwest regions of China ( Emamverdian et al, 2021a , b ), which pose significant risks to human health. An early survey conducted on edible plants in some local markets in China showed that the content of As was remarkably high in the shoots of bamboo species ( Zhao et al, 2006 ).…”