Methyl Jasmonate-Induced Changes in Non- and Antioxidant-Enzymatic Defense in Peppermint (Mentha piperita)

Peppermint (Mentha piperita L.), a herbaceous and perennial species whichis produced mainly for the medicine and food. The peppermint plants were initiated from 10 cm-long rhizome cuttings followed by transferring into pots. The 48 h-treated plants with methyl jasmonate (MJ) concentrations (0, 0.1, 0.5 mM) were assessed for their total soluble proteins, malondialdehyde (MDA), chlorophylls a, b and total, anthocyanin, total carbohydrates, carotenoid, activity of antioxidant guaiacol peroxidase (POD) and superoxide dismutase (SOD) enzymes. The data were analyzed using completely randomized design (CRD) with three replications. Mean comparisons were carried out, using Duncan's multiple range test. MJ treatment caused significant changes in soluble proteins, chlorophylls (a, b and total), MDA, carbohydrates and antioxidant enzymes (SOD and POD) but had no effect on antocyanin and carotenoid. These results indicate that MJ can effectively improve the defense system and antioxidant capacity of peppermint.