Differential induction of enzymes and antioxidants of the antioxidative defense system in Anabaena doliolum exposed to heat stress

✍ Scribed by Yogesh Mishra; Poonam Bhargava; Lal Chand Rai

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 232 KB
• Volume: 30
• Category: Article
• ISSN: 0306-4565
• DOI: 10.1016/j.jtherbio.2005.06.005

✦ Synopsis

Anabaena doliolum subjected to 43, 48, 53 and 58 1C temperature for 1, 2, 3 and 4 h, showed temperature and timedependent increase in H 2 O 2 production and MDA contents. All the measured enzymes of the antioxidative defense system (SOD, CAT, APX and GR) showed increase in their activities at 43 1C after 1 h of treatment, but at higher temperature their activity declined. The content of antioxidants (ASC, GSH, and a-TOC) increased significantly with rise in temperature as well as duration of treatment. This study clearly demonstrates that when enzymatic defense system becomes inactive, the antioxidants (GSH, and a-TOC) are induced to protect the cyanobacterium from heat stress. One of the major roles of these antioxidants appears to be the protection of PSII as reflected by an effect on O 2 evolution up to 53 1C.