Antioxidant enzymes response to medicinal plant of Bakhtiari savory (Satureja bachtiarica Bunge.) affected by density and organic fertilizers in dryland farming conditions

Antioxidant enzymes synthesis in plant is an essential process for increasing the plant's tolerance to abiotic stress. Plant cells and their organs are protected by antioxidant enzymes with removing reactive oxygen species (ROS). To investigate the effect of plant density and organic fertilizers on the antioxidant enzymes activity including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), polyphenol oxidase (PPO), ascorbate peroxidase (APX) and electrolyte leakage (EL) of Bakhtiari savory (Satureja bachtiarica Bunge.), a field experiment was carried out at dryland farming conditions in Research station of Forests and Rangelands of Homand, Damavand, during 2018 and 2019. The results indicated that organic substrates and plant density significantly changed antioxidant enzyme activities (P≤0.05). Under these conditions, cattle manure reduced the antioxidant enzymes of APX, SOD, PPO, and EL. High plant density resulted in less SOD, POD, APX, CAT, and EL compared to low plant density. Compared to control (non- organic fertilizer), cattle manure decreased the activity of SOD, CAT, PPO and EL by 8, 14, 8, and 28%, respectively, in second year-plants. High plant density decreased the activity of SOD, POD, APX, and CAT by 12, 25, 14, and 23%, respectively. The present study can suggest the use of cattle manure and high plant density to reach the optimal growth under dryland farming conditions through controlling antioxidant enzymes production.