Journal of Environmental Biology

Influences of gibberellin and auxin on endogenous plant hormone and starch mobilization during rice seed germination under salt stress

                                                                                       

S. K. Kim¹, T. K. Son², S. Y. Park³, I. J. Lee², B. H. Lee¹, H. Y. Kim⁴ and S. C. Lee²

¹Institute for Bioresources Research, Gyeongbuk Provincial Agril. Technology Administration, Andong 760 891, South Korea

²College of Agricultural & Life Sciences, Kyungpook National University, Daegu 702701, South Korea

³Department of Clinical Pathology, Cheju Halla College, Cheju 690708, South Korea

⁴Division of Environmental Science & Engineering, Keimyung University, Daegu 704701, South Korea

 

 (Received: 01 November, 2004 ; Accepted: 21 March, 2005)

­­

 

 

Abstract : The soaking effects of two plant hormones, gibberellic acid (GA₃) and indole-3-acetic acid (IAA) on dehulled rice seeds exposed to low NaCl stress were investigated. Total soluble and reducing sugars in endosperms of rice seeds soaked with GA₃ (10 µM) increased gradually as germination progressed under low NaCl stress. This increase was more pronounced in IAA-soaked rice seeds than in GA₃–soaked rice seeds. Similarity of α-amylase activity in IAA-soaked germinating rice seeds was much more stimulated than that soaked with GA₃. IAA- and GA₃-soaked rice seeds showed relatively high amounts of endogenous IAA under salt stress. In particular, IAA content increased more in GA₃-soaked rice seeds than in IAA-soaked rice seeds. Furthermore, gibberellin content in IAA-soaked rice seeds showed the highest concentrations among all the treatments. It suggests that recovery effect in starch mobilization and root elongation is in some part regulated by soaking treatment of plant hormones under lower salt stress in rice seed germination.

 

Key words : Plant hormone, Gibberellic acid, IAA, Salinity, Oryza sativa L., Starch.

Copyright © 2006 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).