Defense Mechanisms and Nutrient Displacement in Arabidopsis thaliana upon Exposure to CeO2 and In2O3 Nanoparticles

Published

September 1, 2016

Author(s)

Bryant C. Nelson, Sanem Hosbas Coskun, Chuanxin Ma, Hong Li, Huiyuan Guo, Craig Musante, Jason C. White, Baoshan Xing, Om P. Dhankher

Abstract

Metal-based nanoparticles (NPs) can cause toxicity to terrestrial plants, however there is little understanding of plant defense mechanisms that may counteract nanotoxicity. In the present study, we investigated the defense mechanisms of Arabidopsis thaliana in response to 250 mg/L and 1000 mg/L cerium oxide (CeO2) and indium oxide (In2O3) NPs exposures. Excessive amounts of total reactive oxygen species (ROS) were measured upon exposure to both NPs, demonstrating clear oxidative stress in Arabidopsis. Analysis of ROS scavenger activity indicated that activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD) were significantly elevated upon exposure to CeO2 NPs, while these elevations were only evident for SOD and POD activities in the In2O3 NP treatments. In addition, the activities of glutathione S-transferase (GST) and glutathione reductase (GR) were increased approximately 15% and 51% by 1000 mg/L CeO2 and In2O3 treatment, respectively. Further, the activities of phenylanine ammonialyase (PAL) and polyphenol oxidase (PPO) were highly induced in response to both types of NPs. Additionally, both NPs disrupted the uptake of elemental nutrients as evident from the significantly lower levels of Fe accumulation in Arabidopsis root tissues exposed to CeO2 and In2O3 NPs. These results were further supported by the differential regulation of three iron transporters (FRO, IRT, and FER) at various time points. The findings provide useful mechanistic information for plant detoxification pathways following NP exposures.

Citation

Royal Society of Chemistry Journal Environmental Science: Nano

Volume

3

Pub Type

Journals

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DOI Link

Citation

Nelson, B. , Hosbas, S. , Ma, C. , Li, H. , Guo, H. , Musante, C. , White, J. , Xing, B. and Dhankher, O. (2016), Defense Mechanisms and Nutrient Displacement in Arabidopsis thaliana upon Exposure to CeO2 and In2O3 Nanoparticles, Royal Society of Chemistry Journal Environmental Science: Nano, [online], https://doi.org/10.1039/c6en00189k (Accessed May 10, 2024)