The inductive responses of the antioxidant enzymes by salt stress in the rice ( Oryza sativa L.)

• Published in: Journal of plant physiology Vol. 158; no. 6; pp. 737 - 745
• Main Authors: Lee, Dong Hee, Kim, Young Sang, Lee, Chin Bum
• Format: Journal Article
• Language: English
• Published: Jena Elsevier GmbH 2001; Elsevier
• Subjects: Absorption. Translocation of ions and substances. Permeability; Agronomy. Soil science and plant productions; ascorbate peroxidase; Biological and medical sciences; catalase; Economic plant physiology; Fundamental and applied biological sciences. Psychology; glutathione reductase; H 2O 2; Nutrition. Photosynthesis. Respiration. Metabolism; Plant physiology and development; rice; salt stress; superoxide dismutase; Water and solutes. Absorption, translocation and permeability; H 2O 2; ascorbate peroxidase; superoxide dismutase; salt stress; glutathione reductase; rice; catalase; Oxidative stress; Monocotyledones; Molecular form; Salt resistance; L-Ascorbate peroxidase; Superoxide dismutase; Cereal crop; Oryza sativa; Enzymatic activity; Catalase; Gramineae; Angiospermae; Peroxidase; Root; Enzyme; Induction; Plant leaf; Antioxidant; Gene expression; Hydrogen Peroxides; Salinity; Peroxidases; Spermatophyta; Oxidoreductases; Biological accumulation
• ISSN: 0176-1617; 1618-1328
• DOI: 10.1078/0176-1617-00174

To access contributions of inductive responses of the antioxidant enzymes in the resistance to salt stress, activities of the enzymes were determined in the rice ( Oryza sativaL. cv. Dongjin) plant. In the leaves of the rice plant, salt stress preferentially enhanced the content of H 2O 2 as well as the activities of the superoxide dismutase (SOD), ascorbate peroxidase (APX), and peroxidase specific to guaiacol, whereas it induced the decrease of catalase activity. On the other hand, salt stress had little effect on the activity levels of glutathione reductase (GR). In order to analyze the changes of antioxidant enzyme isoforms against salt stress, plant extracts were subjected to native PAGE. Leaves of the rice plant had two isoforms of Mn-SOD and five isoforms of Cu/Zn-SOD. Fe-SOD isoform was not observed in the activity gels. Expression of Cu/Zn-1, -2, and Mn-SOD-2 isoforms was preferentially enhanced by salt stress. Seven APX isoforms were presented in the leaves of the rice plants. The intensities of APX-4 to -7 were enhanced by salt stress, whereas those of APX-1 to -3 were minimally in changed response to salt stress. There were seven GR isoforms in the leaves of rice plants. Levels of activity for most GR isoforms did not change in the stressed plants compared to the control plants. On the other hand, the levels of activity for most antioxidant enzymes changed little in the roots of stressed plants compared to the control plants. These results collectively suggest that SOD leads to the overproduction of hydrogen peroxide in the leaves of rice plants subjected to salt stress: The overproduction of hydrogen peroxide functions as the signal of salt stress, which induces the induction of specific APX isoforms but not specific GR isoforms under catalase deactivation.