Uptake, Transport, and Transformation of CeO₂ Nanoparticles by Strawberry and Their Impact on the Rhizosphere Bacterial Community

Abstract

Many studies demonstrated that CeO2 nanoparticles (NPs) could protect plant from stress and improve plant growth, with a great application potential in agriculture. However, our knowledge of their fate particularly in asexual plants and their effect on the rhizosphere microbiome is limited. In this study, the transport and transformation of CeO2 NPs in an asexual plantstrawberry (Fragaria × ananassa Duch.)were investigated. The effects of root-exuded/newly formed Ce species on rhizosphere bacterial community were also examined. Strawberries were exposed to CeO2 NPs at 0–2000 mg/L for 45 days via a split-root system in the field. CeO2 NPs were taken up by the exposed mother ramet roots and then translocated to all the mother and daughter ramet tissues. As indicated by the analysis from high-resolution transmission electron microscopy and X-ray absorption near-edge structures, in addition to CeO2 NPs, CePO4, Ce­(III) acetate, and Ce­(III)-cysteine were found in the roots, and CePO4 was present in the rhizosphere soil. The Ce species in the rhizosphere soil decreased the rhizosphere microbial diversity, but stimulated the relative abundance of specific plant growth promoting rhizobacteria. These results provide new insights for understanding the benefits and sustainable applications of NPs.

Engineered Nanomaterials in Soil: Their Impact on Soil Microbiome and Plant Health

“…Inside the soil, the interaction of ENMs with plants potentially affects plant physiology and possibly food security, due to nano-phytotoxicity which has been intensively studied [ 174 , 175 ]. Apart from the harmful effects, the beneficial effects on ENMs-plants interactions at the biochemical, physiological, and genetic levels are also reported by various authors ( Table 1 ) [ 176 , 177 , 178 ]. These effects usually depend on various factors such as the chemical characteristic of ENMs, surface charge, their size, and doses [ 179 , 180 , 181 , 182 , 183 ].…”

In Planta Nanosensors: Understanding Biocorona Formation for Functional Design

“…As an illustrative example, flavonoid signaling in the rhizosphere has been well established, and nanoparticles have previously been shown to form a biocorona rich with flavonoid compounds . These results suggest that the rhizosphere will impact nanoparticle corona composition and subsequent plant uptake and that nanoparticles can interfere with native signaling functions necessary for healthy organism maintenance. ,, …”

“…78 These results suggest that the rhizosphere will impact nanoparticle corona composition and subsequent plant uptake and that nanoparticles can interfere with native signaling functions necessary for healthy organism maintenance. 78,108,110 After the rhizosphere has been navigated and nanoparticles engage directly with the roots, multiple studies have found that positively charged nanoparticles are more readily adsorbed onto and in through root surfaces. 101,104,111,112 However, once inside the plant, the opposite trend occurs, whereby negatively charged nanoparticles promote higher translocation efficiency.…”

Insights into nanoparticle-induced changes in plant photosynthesis

“…Lower concentrations of CeO2 NPs can have a positive effect on photosynthesis (Abbas et al 2020). Treatment with 300 mg L -1 of CeO2 NPs increased the Chl content, net photosynthetic rate, and Rubisco activity in Fragaria ananassa (Dai et al 2020). The application of CeO2 NPs can increase the uptake of Mg 2+ ions, which are a key structural component of the Chl molecule.…”