Rice Science ›› 2023, Vol. 30 ›› Issue (5): 449-458.DOI: 10.1016/j.rsci.2023.03.016

• Research Papers • Previous Articles     Next Articles

Effects of Zinc Oxide Particles with Different Sizes on Root Development in Oryza sativa

Monica Ruffini Castiglione1,2, Stefania Bottega1, Carlo Sorce1,2(), Carmelina SpanÒ1,2   

  1. 1Department of Biology, University of Pisa, Via Luca Ghini, Pisa 13 56126, Italy
    2Centre for Climate Change Impact, University of Pisa, Via del Borghetto, Pisa 80 56124, Italy
  • Received:2022-11-10 Accepted:2023-03-08 Online:2023-09-28 Published:2023-08-14
  • Contact: Carlo Sorce (carlo.sorce@unipi.it)
  • About author:First author contact:#These authors contributed equally to this work


Given the consistent release of zinc oxide (ZnO) nanoparticles into the environment, it is urgent to study their impact on plants in depth. In this study, grains of rice were treated with two different concentrations of ZnO nanoparticles (NP-ZnO, 10 and 100 mg/L), and their bulk counterpart (B-ZnO) were used to evaluate whether ZnO action could depend on particle size. To test this hypothesis, root growth and development assessment, oxidative stress parameters, indole-3-acetic acid (IAA) content and molecules/enzymes involved in IAA metabolism were analyzed. In situ localization of Zn in control and treated roots was also performed. Though Zn was visible inside root cells only following nanoparticle treatment, both materials (NP-ZnO and B-ZnO) were able to affect seedling growth and root morphology, with alteration in the concentration/pattern of localization of oxidative stress markers and with a different action depending on particle size. In addition, only ZnO supplied as bulk material induced a significant increase in both IAA concentration and lateral root density, supporting our hypothesis that bulk particles might enhance lateral root development through the rise of IAA concentration. Apparently, IAA concentration was influenced more by the activity of the catabolic peroxidases than by the protective action of phenols.

Key words: zinc oxide, indole-3-acetic acid, lateral root, rice, bulk particle, nanoparticle