This study aimed to assess the physiological characteristics, phenolic compounds (PCs), antioxidant anzymes, and antioxidant activity of M. piperita under different Zn concentrations (0, 0.025, 0.05, and 0.1 mgL− 1 ) and foliar spraying of methyl jasmonate (distilled water, distilled water + 1% ethanol and 1 and 2 mM of methyl jasmonate) under soilless culture system. According to the findings of this study, Zn omission and the highest Zn level (0.1mgL− 1 ) showed stress conditions on the plants and their effects on the studied traits was different from the other Zn concentrations (0.025 and 0.05mgL− 1 ). In addition, different Zn and MeJA concentrations had special effects on the treated plants. As 1 mM MeJA application significantly enhanced antioxidant activity and the accumulation of PCs of M. piperita in different Zn levels. Rosmarinic acid, as the main PCs, showed a higher content (34.34 mg g DW− 1 ) in 1 mM MeJA and 0.05 mgL− 1 Zn application. In addition, a specific concentration of Zn could promote physiological characteristics such as antioxidant enzyme activities. These findings indicated that different Zn concentrations and exogenous MeJA might encourage the accumulation of PCs and enhanced antioxidant activity of peppermint. It also found that antioxidant enzyme activities modified with Zn and MeJA levels to decrease the injury produced by Zn stress.

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