Impacts of acute ozone stress on superoxide dismutase (SOD) expression and reactive oxygen species (ROS) formation in rice leaves

• Published in: Plant physiology and biochemistry 2013-09, Vol.70, p.396-402
• Main Authors: Ueda, Yoshiaki, Uehara, Naoko, Sasaki, Haruto, Kobayashi, Kazuhiko, Yamakawa, Takashi
• Format: Article
• Language: English
• Subjects: air; animals; Biological and medical sciences; cells; Chloroplasts - drug effects; Chloroplasts - metabolism; crops; Cytosol - drug effects; Cytosol - metabolism; death; Fundamental and applied biological sciences. Psychology; gene expression; Hydrogen peroxide; Hydrogen Peroxide - metabolism; leaves; lipid peroxidation; Lipid Peroxidation - drug effects; MDA; Mitochondria - drug effects; Mitochondria - metabolism; NADP (coenzyme); Organelles - drug effects; Organelles - metabolism; Oryza - drug effects; Oryza - enzymology; Oryza - metabolism; Oryza sativa; Oxidative Stress - drug effects; Ozone; Ozone - pharmacology; physiological response; Plant Leaves - drug effects; Plant Leaves - metabolism; Plant physiology and development; Reactive oxygen species; Reactive Oxygen Species - metabolism; rice; Signal Transduction; Superoxide dismutase; Superoxide Dismutase - metabolism; troposphere
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2013.06.009

Tropospheric ozone is an air pollutant harmful to plants and animals. Its rapid increase at the ground surface has raised serious concern over damage to the quality and yield of agricultural crops. Reactive oxygen species (ROS) are formed in plant cells when that are exposed to a high concentration of ozone, and the ROS are thought to alter gene expression and result in cellular death. Clarification of the ROS formation will provide us with a better understanding of the physiological responses to and signaling pathways of ozone stress in plants. In this study, we investigated the mechanisms of the ROS formation in rice (Oryza sativa L.), the premier crop in Asia. To determine ROS distribution in rice leaves under acute ozone stress, we analyzed superoxide dismutase (SOD) expression, lipid peroxidation, NADPH oxidase activity, and in vivo H2O2 formation. Interestingly, chloroplastic, peroxisomal and mitochondrial SODs down-regulated their expression levels under ozone stress, whereas cytosolic SODs maintained their expression level. Higher lipid peroxidation occurred after the end of ozone exposure, which suggests lipid peroxidation may not be due to ozone directly, but rather to metabolic changes caused by the ozone exposure. Activity of NADPH oxidase did not show significant change. The in vivo analysis indicated accelerated formation of H2O2 about 24 h after the onset of exposure, which suggests that cellular death occurred around this time. •Superoxide dismutases (SODs) are differently induced through acute ozone exposure.•Lipid peroxidation is induced not directly by ozone but through metabolism change.•Activity of NADPH oxidase does not change through acute ozone fumigation.•In vivo H2O2 formation was observed 24 h–48 h from the onset of exposure.