Multiple Method Analysis of TiO₂ Nanoparticle Uptake in Rice (Oryza sativa L.) Plants

Abstract

Understanding the translocation of nanoparticles (NPs) into plants is challenging because qualitative and quantitative methods are still being developed and the comparability of results among different methods is unclear. In this study, uptake of titanium dioxide NPs and larger bulk particles (BPs) at 5 mg/L and 50 mg/L concentrations in rice plant (Oryza sativa L.) tissues was evaluated using three orthogonal techniques: electron microscopy, single-particle inductively coupled plasma mass spectroscopy (spICP-MS) with two different plant digestion approaches, and total elemental analysis using ICP optical emission spectroscopy. In agreement with electron microscopy results, total elemental analysis of plants exposed to TiO2 NPs and BPs at 5 mg/L and 50 mg/L concentrations revealed that TiO2 NPs penetrated into the plant root and resulted in Ti accumulation in above ground tissues at a higher level compared to BPs. spICP-MS analyses revealed that the size distributions of internalized particles differed between the NPs and BPs with the NPs showing a distribution with smaller particles. Acid digestion resulted in higher particle numbers and the detection of a broader range of particle sizes than the enzymatic digestion approach, highlighting the need for development of robust plant digestion procedures for NP analysis. Overall, there was agreement among the three techniques regarding NP and BP penetration into rice plant roots and spICP-MS showed its unique contribution to provide size distribution information.

Different toxicities of nanoscale titanium dioxide particles in the roots and leaves of wheat seedlings

“…Previous studies obtained form wheat and cucumber indicated that TiO 2 NPs could penetrate the roots and enter into root cells. 14,69 In agreement with these ndings, we found that a large number of black grains were detected intercellular spaces of cortical tissues under 5 g nTiO 2 L À1 treatment in the roots (Fig. 6C and E).…”

Development of a suitable detection method for silver nanoparticles in fish tissue using single particle ICP-MS

“…13 The spICP-MS technique was first demonstrated in ultrapure water 14 and has been used to demonstrate its capability to detect silver nanoparticles in ultrapure water. 15 The technique has also been applied to tissues of animals 16 and plants materials (tomato plants, 17 rice plants, 18 ).…”

Endocytosis, intracellular fate, accumulation, and agglomeration of titanium dioxide (TiO2) nanoparticles in the rainbow trout liver cell line RTL-W1

“…Recently, we have established a dosing procedure based on work by Taurozzi et al ( 2013 ), which allows exposure of RTL-W1 cells to TiO 2 NPs under highly controlled conditions, where the NPs are maximally and stably dispersed and hydrodynamic size distribution does not change with time and exposure concentration (Lammel and Sturve 2018 ). In the present study, we make use of this fully characterized system to advance our understanding of the uptake and fate of TiO 2 NPs in fish liver cells using two analytical techniques, transmission electron microscopy (TEM) and single particle inductively coupled plasma mass spectrometry (spICP-MS), which can provide complementary, that is, qualitative and quantitative information on metal NP content and size inside cells at high-resolution (Deng et al 2017 ; Montano et al 2016 ; Reifarth et al 2018 ). Moreover, we use reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) to measure expression levels of genes regulated by the redox-sensitive transcription factor Nrf-2 in order to determine whether TiO 2 NPs do perturb the cellular redox homeostasis at the described exposure conditions.…”