Spermidine Enhances Activities of Detoxification Enzymes in Onion (Allium cepa L.) Seedlings Under Short Term Salinity
Tanjina Islam,
Md. Ismail Hossain,
M. S. Rahaman,
Md. Motiar Rohman
Issue:
Volume 4, Issue 3, May 2016
Pages:
18-23
Received:
26 September 2016
Accepted:
10 October 2016
Published:
3 November 2016
Abstract: In plant, glyoxalases [glyoxalase I (Gly-I, EC: 4.4.1.5) and glyoxalase II (Gly-II, EC: 3.1.2.6)] and glutathione S-transferase (GST, EC: 2.5.1.18) are major detoxification enzymes. On the other hand, spermidine (Spd) is important polyamine (PA) with significant role which interacts with stress protection mechanisms functioning in common against different types of stress. In this study, exogenous Spd was applied on onion seedlings to investigate its protective role through regulation of glyoxalase and GST activities. Continuous increase was observed in the content of methylglyoxal (MG) in onion leaves under salinity, and at 7 day of stress, MG contents increased by 260% over control. Application of Spd reduced the MG contents in saline treated seedlings through increasing glyoxalase mediated detoxification by 21 and 48% at 1 and 3 day of stress, respectively. Salinity increased Gly-I and Gly-II activities which was further increased by Spd upto 3 day of stress. On the other hand, salinity increased GST activity by 14, 55, 93 and 109% over control at 1, 3, 5 and 7 day, respectively. Application of Spd increased the activity in stressed seedlings at 3 day of stress while 21% higher activity was found. However, after 3 days, both glyoxalases and GST activities in Spd treated seedlings decreased and became almost similar to those in drought stressed seedlings without Spd. Considering the results, application of Spd in onion seedlings improved tolerance for short period of salinity.
Abstract: In plant, glyoxalases [glyoxalase I (Gly-I, EC: 4.4.1.5) and glyoxalase II (Gly-II, EC: 3.1.2.6)] and glutathione S-transferase (GST, EC: 2.5.1.18) are major detoxification enzymes. On the other hand, spermidine (Spd) is important polyamine (PA) with significant role which interacts with stress protection mechanisms functioning in common against di...
Show More
