Journal of Nanoparticle Research

, 14:1125

CuO and ZnO nanoparticles: phytotoxicity, metal speciation, and induction of oxidative stress in sand-grown wheat

  • Christian O. Dimkpa
  • Joan E. McLean
  • Drew E. Latta
  • Eliana Manangón
  • David W. Britt
  • William P. Johnson
  • Maxim I. Boyanov
  • Anne J. Anderson
Research Paper

DOI: 10.1007/s11051-012-1125-9

Cite this article as:
Dimkpa, C.O., McLean, J.E., Latta, D.E. et al. J Nanopart Res (2012) 14: 1125. doi:10.1007/s11051-012-1125-9

Abstract

Metal oxide nanoparticles (NPs) are reported to impact plant growth in hydroponic systems. This study describes the impact of commercial CuO (<50 nm) and ZnO (<100 nm) NPs on wheat (Triticum aestivum) grown in a solid matrix, sand. The NPs contained both metallic and non-metallic impurities to different extents. Dynamic light scattering and atomic force microscopy (AFM) assessments confirmed aggregation of the NPs to submicron sizes. AFM showed transformation of ZnO NPs from initial rhomboid shapes in water to elongated rods in the aqueous phase of the sand matrix. Solubilization of metals occurred in the sand at similar rates from CuO or ZnO NPs as their bulk equivalents. Amendment of the sand with 500 mg Cu and Zn/kg sand from the NPs significantly (p = 0.05) reduced root growth, but only CuO NPs impaired shoot growth; growth reductions were less with the bulk amendments. Dissolved Cu from CuO NPs contributed to their phytotoxicity but Zn release did not account for the changes in plant growth. Bioaccumulation of Cu, mainly as CuO and Cu(I)–sulfur complexes, and Zn as Zn-phosphate was detected in the shoots of NP-challenged plants. Total Cu and Zn levels in shoot were similar whether NP or bulk materials were used. Oxidative stress in the NP-treated plants was evidenced by increased lipid peroxidation and oxidized glutathione in roots and decreased chlorophyll content in shoots; higher peroxidase and catalase activities were present in roots. These findings correlate with the NPs causing increased production of reactive oxygen species. The accumulation of Cu and Zn from NPs into edible plants has relevance to the food chain.

Keywords

Environmental health and safety Metal bioaccumulation Metal speciation Metal oxide nanoparticles Oxidative stress Phytotoxicity Solid growth matrix Wheat 

Copyright information

© Springer Science+Business Media B.V. 2012

Authors and Affiliations

  • Christian O. Dimkpa
    • 1
    • 2
  • Joan E. McLean
    • 3
  • Drew E. Latta
    • 4
  • Eliana Manangón
    • 5
  • David W. Britt
    • 1
  • William P. Johnson
    • 5
  • Maxim I. Boyanov
    • 4
  • Anne J. Anderson
    • 1
    • 2
  1. 1.Department of Biological EngineeringUtah State UniversityLoganUSA
  2. 2.Department of BiologyUtah State UniversityLoganUSA
  3. 3.Utah Water Research LaboratoryUtah State UniversityLoganUSA
  4. 4.Biosciences DivisionArgonne National LaboratoryArgonneUSA
  5. 5.Department of Geology and GeophysicsUniversity of UtahSalt Lake CityUSA

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