Evaluation of the expression pattern of Fe-superoxide dismutase and Ferritin-3 genes under salinity in peppermintʼs leaf and root

Salt stress negatively affects many physiological processes in plants. Some of these effects may involve the oxidative damages of cellular components, which can be created by reactive oxygen species (ROS) and prevented by antioxidant enzymes. In this study, FeSOD and Ferritin-3 genes expression under salt stress (0, 25, 50, 75, 100 and 150 mM Nacl) in peppermint using quantitative real time PCR method were investigated. Samples of the leaf and root were collected 24, 48 hour, one week and one month after exposure to stress. Results showed that expression of FeSOD gene up-regulated by increasing salt stress in both leaf and root, but it was higher and more stable in leaves. Expression of this gene was down-regulated after 24 hour, but up-regulated after 48 hour and one week in the leaves, and down-regulated significantly after one month again. In the roots, the FeSOD gene expression was down-regulated after 24 hour, alike leaves, but up-regulated after 48 hour, one week and one month. The expression pattern of Ferritin gene was various in the leaf and root. In the leaves, expression of Ferritin gene was up-regulated in low concentration of salt stress (25 & 50 mM NaCl), then down-regulated by increasing of salinity levels but in the roots, the gene expression down-regulated in all of the salinity levels. The Ferritin gene expression was up-regulated significantly in the early stages of exposure to the salt stress (after 48 hour), and then down-regulated in late time course of exposure to the stress in the leaves. In the roots, the expression of this gene was down-regulated after 24 and 48 hours and one week exposure to the stress, but up-regulated significantly after one month.