Artemisia scoparia essential oil inhibited root growth involves reactive oxygen species (ROS)-mediated disruption of oxidative metabolism: In vivo ROS detection and alterations in antioxidant enzymes

We investigated whether phytotoxicity of Artemisia scoparia essential oil involves a reactive oxygen species (ROS)-mediated stress and alterations in antioxidant enzymes. Effect of Artemisia oil was studied on ROS generation (superoxide anion [O-2(-center dot)], hydrogen peroxide [H2O2] content), proline content, root oxidizability and cell death, and ROS metabolism in wheat. Artemisia oil (0.14-0.70 mg/ml) enhanced the levels of H2O2. O-2(-center dot), and proline suggesting induction of oxidative stress. ROS generation was confirmed by in situ detection of cell death, loss of membrane permeability. H2O2 accumulation, and lipid peroxidation in intact roots. The activities of the scavenging enzymes- superoxide dismutases, catalases, ascorbate- and guaiacol- peroxidases, and glutathione reductases- were significantly elevated in response to Artemisia oil suggesting their induction as a secondary defense mechanism to scavenge increased ROS generation. The study concluded that Artemisia oil caused root growth inhibition involves ROS-mediated cellular damage despite the activation of antioxidant enzyme levels. (C) 2012 Elsevier Ltd. All rights reserved.