The effect of mycorrhizal fungi and growth-promoting rhizobacteria on the activity of antioxidant enzymes of Calotrope seedlings under drought stress

This study aimed to investigate the antioxidant enzyme activities such as catalase, superoxide dismutase, ascorbate peroxidase in Calotrope seedlings (Calotropis procera Ait) inoculated with mycorrhizal and Rhizobacterial microorganisms affected by drought stress under greenhouse conditions during a six-month period. Experiment in three inoculation levels (non-inoculated or control, Rhizophagus irregularis mycorrhizal fungi and Pseudomonas putida Rhizobacterial) and with three levels of drought durations (3, 6, and 12 days irrigation) in a completely randomized design with three replications was conducted. Results revealed that inoculation of mycorrhiza and Pseudomonas Rhizobacterial under drought stress significantly increased the activity of antioxidant enzymes. Maximum activity of catalase (1.57 units of enzyme per mg of fresh weight), superoxide dismutase (17.43 units of enzyme per mg of fresh weight) and ascorbate peroxidase (4.56 units of enzyme per mg of fresh weight) in mycorrhizal seedlings under drought stress for 12 days and also highest amount of peroxidase activity in mycorrhizal (11.96 units of enzyme per mg of fresh weight) and Rhizobacterial (12.9 units of enzyme per mg of fresh weight) seedlings under drought conditions for 12 days were observed.