Iranian Biology Society Journal of Plant Research (Iranian Journal of Biology) 2383-2592 34 3 2021 09 23 Effect of Salicylic Acid on Physiological and Biochemical characteristics of Melissa officinalis L. under Cadmium Stress Effect of Salicylic Acid on Physiological and Biochemical characteristics of Melissa officinalis L. under Cadmium Stress 646 657 1746 FA Monavareh Heidari Department of Biology, Faculty of Basic Sciences, University of Sistan and Baluchestan Sedigheh Esmaeilzadeh Bahabadi Department of Biology, Faculty of Basic Sciences, University of Zabol, Zabol, Iran. Mohammad Sangtarash Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran Journal Article 2019 11 23 Cadmium is one of the heavy metals that causes oxidative stress in plants. In this regard, the use of plant growth regulators such as salicylic acid is suggested as a suitable compound to alleviate the toxic effects of cadmium. This study was conducted to investigate the interaction between cadmium chloride and salicylic acid on growth characteristics, antioxidant enzymes activity, carbohydrate and proline content of lemon balm. This research was carried out in a factorial experiment in a completely randomized design with three replications in a plant physiology research laboratory located at the University of Zabol in 1396. Expriments factors include four different cadmium levels (0, 1, 0.5, 1 μM) and three levels of salicylic acid (0, 0.5, 1 mM). The results showed that different growth characteristics, including root and stem weight, root and shoot length, were decreased by cadmium stress. The addition of SA improved the growth characteristics. Carbohydrate and protein content were reduced by cadmium stress and SA reduced the decline. Antioxidant enzymes activity (catalase, ascorbate peroxidase, Guaiacol peroxidase) as well as malondialdehyde content increased under cadmium stress conditions. While SA decreased malondialdehyde content and antioxidant enzymes activity. These findings suggest that the use of salicylic acid somewhat eliminates some of the toxic effects of cadmium and improved the tolerance of lemon balm under cadmium stress. Cadmium is one of the heavy metals that causes oxidative stress in plants. In this regard, the use of plant growth regulators such as salicylic acid is suggested as a suitable compound to alleviate the toxic effects of cadmium. This study was conducted to investigate the interaction between cadmium chloride and salicylic acid on growth characteristics, antioxidant enzymes activity, carbohydrate and proline content of lemon balm. This research was carried out in a factorial experiment in a completely randomized design with three replications in a plant physiology research laboratory located at the University of Zabol in 1396. Expriments factors include four different cadmium levels (0, 1, 0.5, 1 μM) and three levels of salicylic acid (0, 0.5, 1 mM). The results showed that different growth characteristics, including root and stem weight, root and shoot length, were decreased by cadmium stress. The addition of SA improved the growth characteristics. Carbohydrate and protein content were reduced by cadmium stress and SA reduced the decline. Antioxidant enzymes activity (catalase, ascorbate peroxidase, Guaiacol peroxidase) as well as malondialdehyde content increased under cadmium stress conditions. While SA decreased malondialdehyde content and antioxidant enzymes activity. These findings suggest that the use of salicylic acid somewhat eliminates some of the toxic effects of cadmium and improved the tolerance of lemon balm under cadmium stress. https://plant.ijbio.ir/article_1746_442cde81694ca09a626eeddefd1b74ca.pdf