JEB logo

Journal of Environmental Biology

pISSN: 0254-8704 ; eISSN: 2394-0379 ; CODEN: JEBIDP

About Journal
    Editorial Board
    Reviewer Panel
    RnD Division
    Subscription Info
    Contact Journal
 
Read Journal
    Current Issue
    Journal Archives
 
For Authors
    Authoring Guidelines
    Publication Process
    Track Paper Status
 

Search the Journal web-site through Google:


        Abstract - Issue July 2009, 30 (4)                                                                                                             Back



Abstract _15

Involvement of calcium and calmodulin in oxidative and temperature

stress of Amaranthus lividus L. during early germination

 

 

Soumen Bhattacharjee

Post Graduate Department of Botany, Hooghly Mohsin College, Chinsurah - 712 101, India

(Received: August 24, 2007; Revised received: April 24, 2008; Accepted: July 28, 2008)

 

Abstract: Both heat and chilling caused reduction in membrane protein thiol level and increased accumulation of thiobarbituric acid reactive substances in 72 hr old germinating tissues (indicators of oxidative stress) and reduced germination and early growth performances. Calcium chelator EGTA [Ethylene glycol-bis(2-aminoethylether)-N,N,N?,N, tetra acetic acid] calcium channel blocker LaCl3 (Lanthanum chloride) and calmodulin inhibitor TFP (trifluroperazine) aggravated these effects of heat and chilling and added calcium reversed them. Imposition of heat and chilling stress during early germination also causes accumulation of reactive oxygen species (ROS) like O2- and H2O2. Calcium treatment significantly reduced the accumulation of both the toxic ROS, while EGTA, LaCl3 and TFP treatment enhanced the accumulation. Activities of antioxidative enzymes catalase (CAT), ascorbate peroxidase (APOX) and glutathione reductase (GR) and total thiol content decreased significantly under both heat and chilling stress in germinating Amaranthus seedlings. Seedlings raised with Ca2+ treatment under heat and chilling stress exhibit higher activities of CAT, GR and APOX and total thiol level than the untreated plants. EGTA, LaCl3 and TFP treatment, on the other hand significantly reduce the activities of all anti-oxidative enzymes and total thiol level. The work clearly supports the view that Ca2+-signalling pathway plays significant role in limiting heat and chilling induced oxidative stress by up-regulating antioxidative defense during recovery phase of post- germination event in Amaranthus lividus.

Key words: Heat, Chilling, Germination, Calcium, Calmodulin, Oxidative stress

??????? PDF of full length paper is available online

 

 

 

 

Copyright ? 2009 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).