Synchrotron Radiation Spectroscopy and Transmission Electron Microscopy Techniques to Evaluate TiO2 NPs Incorporation, Speciation, and Impact on Root Cells Ultrastructure of Pisum sativum L. Plants

Abstract

Biosolids (Bs) for use in agriculture are an important way for introducing and transferring TiO2 nanoparticles (NPs) to plants and food chain. Roots of Pisum sativum L. plants grown in Bs-amended soils spiked with TiO2 800 mg/kg as rutile NPs, anatase NPs, mixture of both NPs and submicron particles (SMPs) were investigated by Transmission Electron Microscopy (TEM), synchrotron radiation based micro X-ray Fluorescence and micro X-ray Absorption Near-Edge Structure (µXRF/µXANES) and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). TEM analysis showed damages in cells ultrastructure of all treated samples, although a more evident effect was observed with single anatase or rutile NPs treatments. Micro-XRF and TEM evidenced the presence of nano and SMPs mainly in the cortex cells near the rhizodermis. Micro-XRF/micro-XANES analysis revealed anatase, rutile, and ilmenite as the main TiO2 polymorphs in the original soil and Bs, and the preferential anatase uptake by the roots. For all treatments Ti concentration in the roots increased by 38–56%, however plants translocation factor (TF) increased mostly with NPs treatment (261–315%) and less with SMPs (about 85%), with respect to control. In addition, all samples showed a limited transfer of TiO2 to the shoots (very low TF value). These findings evidenced a potential toxicity of TiO2 NPs present in Bs and accumulating in soil, suggesting the necessity of appropriate regulations for the occurrence of NPs in Bs used in agriculture.

Nano and submicron fluorescent polystyrene particles internalization and translocation in seedlings ofCichorium endiviaL.

“…This could reflect the difficulty of these larger particles to enter the root and to move within the tissues. 56 Results were consistent with ATR-IR measurements confirmed that C. endivia seedlings absorbed more easily nPS.…”

“…This could reflect the difficulty of these larger particles to enter the root and to move within the tissues. 56 Results were consistent with ATR-IR measurements confirmed that C. endivia seedlings absorbed more easily nPS. Worthy of attention was the presence of plasmolysis in all tissues of all treated samples that could be related to a reduced water absorption.…”

Polystyrene nanoplastics affect seed germination, cell biology and physiology of rice seedlings in-short term treatments: Evidence of their internalization and translocation

“…Also in this case, the treatments were able to alter the localization pattern of the probe, indicating the direct effects of the PSNPs on the integrity of the membranes, belonging to different tissues and organs. As demonstrated for metal nanoparticles (Muccifora et al, 2021) local production of ROS, would lead to the degradation of structures such as cell membrane and cell wall, allowing possible PSNPs entrance and movement. These data were supported by the observations at the TEM (Fig.…”

Titanium dioxide nanoparticles enhance the detrimental effect of polystyrene nanoplastics on cell and plant physiology of Vicia lens (L.) Coss. & Germ. seedlings

“…This suggests that treatment with nano-TiO 2 would induce root tissue damage by facilitating the entry and uptake of nano-PS into the plant body. In fact, in a previous work (Muccifora et al, 2021), it has been shown that anatases nano-TiO 2 are able to produce crossing ruptures of cell wall and plasmalemma of adjacent cell root, in this way enhancing nanoplastic uptake.…”