Journal of Environmental Biology

Response of ultraviolet-B induced antioxidant defense system

in a medicinal plant, Acorus calamus

 

Rima Kumari, Suruchi Singh and S.B. Agrawal*

 

Laboratory of Air Pollution and Global Climate Change, Department of Botany, Banaras Hindu University, Varanasi - 221 005, India

(Received: September 01, 2009; Revised received: December 06, 2009; Accepted: December 10, 2009)

 

Abstract: Ultraviolet-B (UV-B) radiation generates an oxidative stress in plant cells due to excessive generation of reactive oxygen species (ROS). ROS can denature enzymes and damage important cellular components. In the present study, an important medicinal plant Acorus calamus (Sweet flag) was subjected to two doses of supplemental UV-B radiation (sUV-B): sUV₁ (+1.8 kJ m^-2 d^-1) and sUV₂ (+3.6 kJ m^?2 d^?1) to evaluate the relative response of antioxidant defense potential.? Stimulation of activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) was observed at initial growth period while the activities of CAT and SOD decreased at later age of sampling. sUV-B induced lipid peroxidation (LPO) was observed showing alteration of membrane properties. No definite trend of change was observed for ascorbic acid (AsA), while increaments in thiol, proline, phenol and protein contents were observed due to sUV-B. Results suggested that sUV-B radiation may stimulate the enzymatic and non-enzymatic defense system of Acorus plants, showing its better adaptation at lower dose of sUV-B.

Key words: Reactive oxygen species, Acorus calamus L., supplemental UV-B, Antioxidants

Copyright ? 2010 Triveni Enterprises. All rights reserved. No part of the Journal can be reproduced in any form without prior permission. Responsibility regarding the authenticity of the data, and the acceptability of the conclusions enforced or derived, rest completely with the author(s).