Open Access

ARTICLE

Titanium Dioxide Nanoparticles Promote Root Growth by Interfering with Auxin Pathways in Arabidopsis thaliana

by Jiali Wei, Ying Zou, Ping Li, Xiaojun Yuan

Shanghai Key Laboratory of Bio-Energy Crops, Research Center for Natural Products, Plant Science Center, School of Life Sciences, Shanghai University, Shanghai 200444, China

* Corresponding Author: Jiali Wei. Email:

Phyton-International Journal of Experimental Botany 2020, 89(4), 883-891. https://doi.org/10.32604/phyton.2020.010973

Received 13 April 2020; Accepted 29 April 2020; Issue published 09 November 2020

Abstract

TiO₂ nanoparticles (nano-TiO₂) are widely used in the world, and a considerable amount of nano-TiO₂ is released into the environment, with toxic effects on organisms. In the various species of higher plants, growth, including seed germination, root elongation, and biomass accumulation, is affected by nano-TiO₂. However, the underlying molecular mechanisms remain to be elucidated. In this study, we observed that nano-TiO₂ promoted root elongation in a dose-dependent manner. Furthermore, we found that nano-TiO₂ elevated auxin accumulation in the root tips of the auxin marker lines DII-VENUS and DR5:: GUS, and, correspondingly, quantitative real-time PCR analysis revealed that nano-TiO₂ increased the expression levels of auxin biosynthesis- and transportrelated genes. GFP fluorescence observation using transgenic PIN2-GFP indicated that nano-TiO₂ promoted root growth by inducing PIN2 accumulation. Thus, we propose that nano-TiO₂ promote root growth in Arabidopsis thaliana by altering the expression levels of auxin biosynthesis- and transport-related genes.

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Citations