Plant Growth Regulation

, Volume 46, Issue 3, pp 209–221

Drought Induces Oxidative Stress and Enhances the Activities of Antioxidant Enzymes in Growing Rice Seedlings

Article

DOI: 10.1007/s10725-005-0002-2

Cite this article as:
Sharma, P. & Dubey, R.S. Plant Growth Regul (2005) 46: 209. doi:10.1007/s10725-005-0002-2
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Abstract

When rice seedlings grown for 10 and 20 days were subjected to in vitro drought stress of −0.5 and −2.0 MPa for 24 h, an increase in the concentration of superoxide anion (O2.−), increased level of lipid peroxidation and a decrease in the concentration of total soluble protein and thiols was observed in stressed seedlings compared to controls. The concentration of H2O2 as well as ascorbic acid declined with imposition of drought stress, however glutathione (GSH) concentration declined only under severe drought stress. The activities of total superoxide dismutases (SODs) as well as ascorbate peroxidase (APX) showed consistent increases with increasing levels of drought stress, however catalase activity declined. Mild drought stressed plants had higher guaiacol peroxidase (GPX) and chloroplastic ascorbate peroxidase (c-APX) activity than control grown plants but the activity declined at the higher level of drought stress. The activities of enzymes involved in regeneration of ascorbate i.e. monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) were higher in drought stressed plants compared to controls. Results suggest that drought stress induces oxidative stress in rice plants and that besides SOD, the enzymes of ascorbate-glutathione cycle, which have not been studied in detail earlier under stressful conditions, appear to function as important component of antioxidative defense system under drought stress.

Keywords

Antioxidative enzymesDrought stressLipid peroxidationOryza sativaOxidative stressSuperoxide

Abbreviations

AsA

ascorbate

CAT

catalase

c-APX

chloroplastic ascorbate peroxidase

DHA

dehydroascorbate

DHAR

dehydroascorbate reductase

GPX

guaiacol peroxidase

GR

glutathione reductase

GSH

glutathione

GSSG

oxidized glutathione

MDHAR

monodehydroascorbate reductase

SOD

superoxide dismutase

TBARS

thiobarbituric acid reactive substances

Copyright information

© Springer 2005

Authors and Affiliations

  1. 1.Department of Biochemistry, Faculty of ScienceBanaras Hindu UniversityVaranasiIndia