Biological responses of <i>Vicia faba</i> seedlings to the imidazolium-based ionic liquid 1-hexyl-3-methylimidazolium chloride in soil

Abstract

Although there are a few studies on the toxicity of ionic liquids (ILs), relatively little is known about their toxic effects on plants in soil. In the present study, the toxic effects of 1-hexyl-3-methylimidazolium chloride ([Hmim]Cl) in the soil on Vicia faba seedlings and the influences of [Hmim]Cl on the physicochemical properties of the soil were studied. Organic matter content, pH, and conductivity of the tested soil were significantly altered at [Hmim]Cl concentrations greater than 1000 mg kg(-1) . Moreover, shoot length, root length, dry weight, and pigment content of the V. faba seedlings were greatly inhibited when the [Hmim]Cl concentration was greater than 500 mg kg(-1) . The roots were the most seriously affected organ and stopped growing at 3000 mg kg(-1) . In addition, [Hmim]Cl caused an increase in the level of reactive oxygen species at [Hmim]Cl concentrations above 250 mg kg(-1) that resulted in lipid peroxidation, DNA damage, and oxidative stress in the V. faba seedlings. The present study provides information that is useful for evaluation of the environmental safety of ILs in soil. Environ Toxicol Chem 2016;35:1502-1510. © 2015 SETAC.