Evaluation of hydrogen peroxide, proline, malondialdehyde and antioxidant enzymes activity In two medicinal plants (Anethum graveolens) and coriander (Coriandrum sativum) under salt stress conditions

The present study was carried out to evaluate the amount of hydrogen peroxide, proline, malondialdehyde and antioxidant enzymes activity of two medicinal plants. Coriander and dill plants were subjected to salinity stress in greenhouse of Faculty of Agriculture and Natural Resources, University of Tehran. The experiment was a factorial based on randomized complete block design with three replications. The treatments consisted of three levels of salt stress including control (no stress), 60 and 120 millimolar sodium chloride salt, and two medicinal plants (coriander and dill). The evaluated traits included the concentration of hydrogen peroxide, malondialdehyde, proline and antioxidant activity of superoxide dismutase, catalase and guaiac peroxidase. The results show that salinity stress increases the amount of hydrogen peroxide, malondialdehyde and proline. With increasing salinity stress, their concentration increased significantly in both medicinal plants. The increase in the roots and dill plants was higher, indicating higher sensitivity of this plant to salinity stress. Also, salinity stress increased the activity of antioxidant enzymes. The activity of all three enzymes evaluated in the root was higher than the shoots. In the dill plant, the activity of the catalase enzyme was much higher than the coriander. However, the two evaluated plants did not differ significantly in terms of the level of activity of the superoxide dismutase and peroxidase enzymes.