Metabolomics analysis of TiO2 nanoparticles induced toxicological effects on rice (Oryza sativa L.)

• Published in: Environmental pollution (1987) Vol. 230; pp. 302 - 310
• Main Authors: Wu, Biying, Zhu, Lizhong, Le, X. Chris
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2017
• Subjects: Metabolic profiling; Nanoparticles; Rice; Titanium dioxide; Nanoparticles; Metabolic profiling; Titanium dioxide; Rice
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2017.06.062

The wide occurrence and high environmental concentration of titanium dioxide nanoparticles (nano-TiO2) have raised concerns about their potential toxic effects on crops. In this study, we employed a GC-MS-based metabolomic approach to investigate the potential toxicity of nano-TiO2 on hydroponically-cultured rice (Oryza sativa L.) after exposed to 0, 100, 250 or 500 mg/L of nano-TiO2 for fourteen days. Results showed that the biomass of rice was significantly decreased and the antioxidant defense system was significantly disturbed after exposure to nano-TiO2. One hundred and five identified metabolites showed significant difference compared to the control, among which the concentrations of glucose-6-phosphate, glucose-1-phosphate, succinic and isocitric acid were increased most, while the concentrations of sucrose, isomaltulose, and glyoxylic acid were decreased most. Basic energy-generating ways including tricarboxylic acid cycle and the pentose phosphate pathway, were elevated significantly while the carbohydrate synthesis metabolism including starch and sucrose metabolism, and glyoxylate and dicarboxylate metabolism were inhibited. However, the biosynthetic formation of most of the identified fatty acids, amino acids and secondary metabolites which correlated to crop quality, were increased. The results suggest that the metabolism of rice plants is distinctly disturbed after exposure to nano-TiO2, and nano-TiO2 would have a mixed effect on the yield and quality of rice. [Display omitted] •TiO2 nanoparticles disturb metabolic flux in rice.•Tricarboxylic acid cycle and the pentose phosphate pathway are elevated significantly.•Starch and sucrose metabolism, and glyoxylate and dicarboxylate metabolism are inhibited significantly.•The non-enzymatic antioxidant is significantly elevated. We identified and analyzed the disturbed metabolomic pathways in rice after exposure to nano-TiO2, using the GC-MS-based metabolomics approach coupled with multivariate analysis.