Evaluation of relative toxicity caused by deicing agents on photosynthesis, redox homeostasis, and the osmoregulatory system in creeper-type plants

Addressing the deterioration effects due to chlorine salt use as an anti-freezing agent to prevent the deposition of ice on roads during heavy snowfall is a serious issue to protect the ecosystem. Therefore, the present study was conducted to determine the effects caused by deicing agents on three different creeper plant species that commonly grow on roadsides, such as Trachelospermum asiaticum, Euonymus fortunei, and Gelsemium sempervirens. The two chlorine salts calcium chloride (CaCl2) and magnesium chloride (MgCl2) were applied to plants either as a splash or spray in different concentrations at different intervals. After 6days of treatments, the results suggested that application of both CaCl2 and MgCl2 affected the chlorophyll content and physiological processes of the creepers in a dose-dependent manner. Further analysis of oxidative stress related parameters such as lipid peroxidation, superoxide, and hydrogen peroxide content showed that both CaCl2 and MgCl2 affected redox homeostasis. While the application of deicing agents induced the activities of antioxidant enzymes, they also decreased the content of ascorbate and proline, which are efficient osmolytes, in the dose-dependent manner. Nevertheless, comparatively oxidative stress induced by CaCl2 is higher than the MgCl2 in all three creeper-type plants included in our analysis; still the frequent application and higher concentration of both deicing agents interrupt the growth of roadside vegetation. Despite the relative toxicity of the deicers, T. asiaticum was affected lesser than E. fortunei and G. sempervirens.