The effect of 1-ethyl-3-methylimidazolium chloride on oxidative stress and the functioning of the photosynthetic apparatus in maize seedlings – the modulatory role of exogenous ascorbic acid

Ionic liquids (ILs) are widely used chemical compounds that may pose potential risks to the environment. In the present study, the effects of 1-ethyl-3-methylimidazolium chloride (EMIMCl) on growth, photosynthetic performance, and oxidative stress in maize ( Zea mays L.) seedlings were evaluated, and the role of exogenous L-ascorbic acid (AsA) in modulating plant responses to this stress was investigated. Plants were cultivated in soil contaminated with EMIMCl at concentrations ranging from 1 to 1000 mg·kg ^-1 of soil dry weight and treated with AsA at concentrations of 0.5–2 mM. EMIMCl significantly inhibited plant growth, reduced photosynthetic pigment content, and impaired chlorophyll fluorescence parameters, accompanied by increased hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) levels, indicating the induction of oxidative stress. Moderate doses of AsA partially alleviated EMIMCl-induced toxicity, whereas higher AsA concentrations under severe EMIMCl contamination intensified stress symptoms. These findings demonstrate a dose-dependent and biphasic role of AsA in maize responses to EMIMCl-induced stress.