Metabolomics Reveal Size-Dependent Impacts of Cerium Oxide Nanoparticles on Grains of Barley (Hordeum Vulgare L.)

Author

Naum Jepkemei Kirwa, Missouri State UniversityFollow

Date of Graduation

Fall 2022

Degree

Master of Science in Chemistry

Department

Chemistry and Biochemistry

Committee Chair

Cyren Rico

Abstract

Plants are exposed to emerging contaminants including nanoparticles, due to the novel but wide uses of these materials. However, researchers have shown contradicting effects of CeO₂-NPs on barley grains with focus mostly on concentration effects and not sizes of these CeO₂-NPs. Therefore, this study aimed at comparing the effects of 0nm (control), 8nm, and 40nm (250 mg CeO₂-NPs/kg soil) on the metabolite profile of barley grains. GC-FID and GC-QTOF-MS were used to measure fatty acid contents and metabolomic changes respectively. GC-FID analysis revealed that palmitic acid, oleic acid, linoleic acid, and the total fatty acid concentrations were not affected, although linolenic acid was increased by 8nm CeO₂-NPs. Interestingly, most sugar metabolites (UDP-N-acetylglucosamine, sorbitol, arabitol, digalacturonic acid, lyxitol, 1,5-anhydroglucitol, and ribose) were decreased by 8nm CeO₂-NPs but increased by 40nm CeO₂-NPs except 1-Kestose. Other sugars (erythritol, beta-gentibiose, glucoheptulose, N-acetylmannosamine, methylmaleic acid, and maltitol) were decreased by both CeO₂-NPs except maltotriitol, ribitol, and glycerol. Amino acid metabolites (N-acetylserine and alanine) were also decreased by both CeO₂-NPs while tyramine was increased. Antioxidant metabolites (ferulic acid and vanillic acid) were increased in treated grains compared to control, while 4-hydroxycinnamic acid was decreased by both 8nm and 40nm CeO₂-NPs. Surprisingly, all fatty acid metabolites were increased by both sizes of CeO₂-NPs except pentadecanoic acid treated with 8nm CeO₂-NPs. Overall, these findings indicate that CeO₂-NPs can have size-dependent but subtle effects on the metabolite profile and biochemical pathways of barley grains. Future studies should investigate if those biochemical changes can have effects in the succeeding generations.

Keywords

amino acid, antioxidant, fatty acid, metabolites, plants, sugar

Subject Categories

Analytical Chemistry | Environmental Chemistry

Copyright

© Naum Jepkemei Kirwa

Recommended Citation

Kirwa, Naum Jepkemei, "Metabolomics Reveal Size-Dependent Impacts of Cerium Oxide Nanoparticles on Grains of Barley (Hordeum Vulgare L.)" (2022). MSU Graduate Theses. 3808.
https://bearworks.missouristate.edu/theses/3808