Impact of Titanium Dioxide Nanoparticles on Cd Phytotoxicity and Bioaccumulation in Rice (Oryza sativa L.)

Abstract

The impact of engineered nanoparticles (ENPs) on the migration and toxicity of coexisting pollutants is still unclear, especially in soil media. This study aims to evaluate the impact of titanium dioxide nanoparticles (TiO2 NPs) on the phytotoxicity of cadmium (Cd) to Oryza sativa L., and the migration of cadmium (Cd) in the soil-rice system. Three different Cd stress groups (C1 group: 1.0 mg kg−1, C2 group: 2.5 mg kg−1 and C3 group: 5.0 mg kg−1) were set in the pot experiment, and the target concentration of TiO2 NPs in each group were 0 mg kg−1 (T0), 50 mg kg−1 (T1), 100 mg kg−1 (T2) and 500 mg kg−1 (T3). Plant height and biomass decreased with the increasing of Cd content in paddy soil. TiO2 NPs could lower the phytotoxicity of Cd in terms of the changes in the morphological and biochemical characteristics, especially in the tillering and booting stage. In the tillering stage, TiO2 NPs addition caused a significant increase in plant height, biomass and the total chlorophyll content in the leaves of Oryza saliva L. In the booting stage, TiO2 NPs addition caused a 15% to 32% and 24% to 48% reduction of malondialdehyde (MDA) content for the C2 and C3 group, respectively, compared to that of the respective control treatment (T0). TiO2-NPs addition reduced the activity of peroxidase (POD) in the leaves in the booting and heading stage, and the activity of catalase (CAT) in the tillering stage. In the C1 and C2 group, the grain Cd content in the 100 and 500 mg kg−1 TiO2 NPs treatments reached 0.47–0.84 mg kg−1, obviously higher than that of the treatment without TiO2 NPs (0.27–0.32 mg kg−1), suggesting that TiO2-NPs could promote Cd migration in the soil-rice system.

Pollution and Ecological Risk Evaluation of Heavy Metals in the Soil and Sediment around the HTM Tailings Pond, Northeastern China

“…Soil and sediment samples were air dried, and passed through a 2-mm sieve. Plant samples were washed and dried at 40 °C to a constant weight in a drying oven [ 22 ]. Each sample was conducted in triplicate.…”

“…All the acid used in the digestion process was guaranteed reagent level (GR, 99.8%). Crop grains were digested with the HNO 3 -hClO 4 mixed-acid digestion method, 1.0 g plant samples were added into a conical flask (150 mL), and 20 mL HNO 3 -hClO 4 mixed-acid (4:1, v/v ) were added into the conical flask, and heated on an electric hot plate [ 22 ]. The concentrations of heavy metals in the extractants and water samples were measured by Inductively Coupled Plasma Mass Spectrometry (Agilent 7700× ICP-MS).…”

“…Water samples were filtered with a syringe filter (0.45 µm), and acidified the samples (pH < 2) with HNO 3 (1 mol L −1 ), stored in the fridge at 4 • C. Soil and sediment samples were air dried, and passed through a 2-mm sieve. Plant samples were washed and dried at 40 • C to a constant weight in a drying oven [22]. Each sample was conducted in triplicate.…”

TiO2 Nanoparticles and Their Effects on Eukaryotic Cells: A Double-Edged Sword

“…In rice ( Oryza sativa ), an increase of hydrogen peroxide (H 2 O 2 ) production, membrane injury and rate of root cell death was observed at higher concentrations, likely connected to an increase in oxidative stress [ 15 ]. On the other hand, TiO 2 NPs seemingly boosted chlorophyll content, biomass, and increased phosphorus and protein grain content [ 14 , 15 ], even when another toxicant such as cadmium was present [ 106 ]. The after-expositional increase in rice biomass and photosynthetic activity was also reported by, e.g., Zhang et al [ 107 ].…”

Assessment of TiO2 Nanoparticles on Maize Seedlings and Terrestrial Isopods Under Greenhouse Conditions

“…For instance, as a country, Mexico has made progress and contributed to the generation of knowledge on environmental contamination caused by NPs in agriculture and natural soil (Delgado-Ramos 2014;Pérez-Hernández et al 2020;Pérez-Moreno et al 2019). In other countries as China, researchers have proposed the TiO 2 NPs in the decontamination of heavy metals (Cd, As, Pb, and others) in association with plants of maize (Lian et al 2020), rice (Zhang et al 2020;Wu et al 2021), wheat (Wu et al 2020), among others. Besides, the advances and numerous and intense investigations in nanotechnology for the country China suggest that synthesis of TiO 2 NPs or the combination with other nanomaterials could be contributing to the remediation of water and soils and in applications in the agricultural sector, thus reducing the impacts on the environment (Liu et al 2020;Gao et al 2020).…”