the effects of salicylic acid and melatonin elicitors on the antioxidant enzymes activity and morphological characteristics of acorus calamus under drought stress

Medicinal plants improve human health, strengthen the immune system, reduce inflammation, and facilitate the treatment of diseases. to investigate the effect of drought stress (after 10 and 20 days of water withdrawal, representing mild and severe drought stress, respectively) and melatonin and salicylic acid on the biochemical and morphological indicators of the acorus calamus medicinal plant, an experiment was conducted. results showed that using melatonin and salicylic acid increased the activity of peroxidase enzyme under drought conditions. also, salicylic acid increased the activity of catalase enzyme in mild drought stress. the application of melatonin and salicylic acid under severe drought stress increased the activity of the catalase enzyme.  under drought stress conditions, the use of salicylic acid and melatonin led to an increase in plant dry weight compared to normal conditions. also using melatonin under severe drought conditions resulted in an increase in dry weight in comparison with the control treatment. in conclusion, while the plant’s responses to stress and elicitors differed across various characteristics, it can generally be stated that salicylic acid and melatonin positively influence the biochemical and morphological traits of acorus calamus under severe and mild drought stress conditions.