Toxic effect and mechanism of four ionic liquids on seedling taproots
of Arabidopsis thaliana
Received: 3 January 2017 /Accepted: 27 February 2018 /Published online: 12 March 2018
Springer-Verlag GmbH Germany, part of Springer Nature 2018
Arabidopsis thaliana was selected as model organisms to investigate the toxic effect and mechanism of four kinds of imidazolium
and pyridinium ionic liquids (ILs) on plant seedling taproots. After exposure to ILs, the growth of seedling taproots was
significantly inhibited in a dose-dependent manner. The toxicity of ILs on seedling taproots was [Bmim][BF
] > [Bmpy][BF
> [Bmim][Br] > [Bmpy][Br]. The reduction of seedling root cell vitality, aggravation of seedling root cell death, and repression of
gravitropic growth responses were observed. The amounts of H
and ROS in seedlings were enhanced with increasing
concentrations of ILs. Moreover, the expression levels of cdc2a and pcna1 genes were decreased after exposure to ILs. Our
results suggest that ILs can induce the overproduction of ROS in A. thaliana seedling taproots and thus cause oxidative damage to
seedling taproots. Meanwhile, ILs alter the expression patterns of two cell cycle-related genes and hence cause the seedling
taproot growth inhibition. This work provides an integrated understanding of the toxic effect and mechanism of ILs on
A. thaliana seedlings at the molecular and physiological level and also provides theoretical basis and reference for the environ-
mental safety evaluation of ILs, prior to their widespread use and release.
Keywords Ionic liquids
Ionic liquids (ILs) are novel organic salts with the excellent
properties that have enormous application potential for indus-
trial production and analytical chemistry (Sheldon 2001;
Anderson and Armstrong 2003; Luo et al. 2004). The physical
and chemical properties of ILs could be varied by changing
their cationic and anionic moieties (Ueno et al. 2010).
Substitution of ILs for traditional solvents could potentially
improve environmental health while saving industry billions
of dollars in future environmental mitigation and clean-up
(Brennecke and Maginn 2001; Karadas et al. 2010).
Nevertheless, ILs should not be considered, or described as
totally Bgreen^ solvents (Swatloski et al. 2003).
The unknown toxicity, potentially hazardous properties,
and stability for many ILs need to make research urgently
(Rogers and Seddon 2003; Liu et al. 2014). The high solubil-
ity of ILs would result in unimpeded transport of them be-
tween groundwater, soil, and organism, but lack of efficiently
removes from environmental mediums (Pham et al. 2016). It
is not well known whether the ILs will cause potential toxicity
and ecological impact for environment and organisms, as well
as their damage degree. Pyridinium, imidazolium, and
pyrrolidinium ILs have been nominated to the US National
Toxicology Program (NTP) for toxicological testing, based
upon their widespread interest as possible alternatives to or-
ganic solvents (Docherty and Kulpa 2005). Thus, it is critical
to determine the toxicities and environmental fate of ILs prior
to their release into the environment.
Ming Li and Yonglai Xue contributed equally to this work.
Responsible editor: Philippe Garrigues
Electronic supplementary material The online version of this article
(https://doi.org/10.1007/s11356-018-1621-2) contains supplementary
material, which is available to authorized users.
* Yonglai Xue
* Daolin Du
Institute of Environment and Ecology, Institute of Environmental
Health and Ecological Security, School of the Environment and
Safety Engineering, Jiangsu University, Zhenjiang 212013, People’s
Republic of China
Environmental Science and Pollution Research (2018) 25:14703–14712