Pal, Sikander .
Mitigation of Cu induced Oxidative stress by epibrassinolide and spermidine application through enhnacing¬†antioxidant mechanism of radish seedlings.
In order to examine whether exogenously applied brassinosteriods (BRs) and polyamines (PAs) could modify the working of the free radical scavenging system and Cu induced oxidative stress levels, in 7 d old radish (Raphanus sativus L. cv. Pusa chetki) seedlings. Seedlings were treated with epibrassinolide (EBL)- an potent BR and spermidine (SPD)- an active PA alone or in combination with Cu metal and stress-evoked changes in antioxidative enzymes such as superoxide dismutase (SOD) (EC 220.127.116.11), catalase (EC 18.104.22.168), guaiacol peroxidase (EC 22.214.171.124), glutathione reductase (GR) (EC 126.96.36.199) activities, and radical scavenging capacities were determined. Malondialdehyde, proline, total phenols and ascorbic acid contents under the stress period were also determined. Exogenous application of EBL and SPD alone or in combination with Cu metal showed significant decrease in guaiacol peroxidase, whereas, increase in SOD, CAT and GR activities were recorded under the same treatments. Major improvement in free proline, ascorbic acid and total phenolics were observed for various EBL and SPD treatments. EBL and SPD treatments were also able to enhance free radical scavenging capacities of radish seedlings when compared to metal stress and control values, as indicated by higher values of DPPH, deoxyribose and reducing power assays. In summary, both EBL and SPD were able to modulate the activities of antioxidative enzymes and free radical scavenging potential to ameliorate the Cu induced oxidative stress intensity. Moreover, the co-application of EBL and SPD were also observed to show synergistic interactions in enhancing the stress tolerance of the radish plants against Cu stress.
Extensive literature survey has revealed paucity of information regarding the mitigation of heavy metal induced oxidative stress by the co-application of BRs and PAs. One of the best plant models to study the effects of BRs and PAs on the antioxidant potential under metal stress is radish seedlings (Raphanus sativus L.)- an important root vegetable.
The present investigation revealed for the first time that the co-application of EBL and SPD could be used to alleviate the heavy metal induced oxidative stress damages in radish plants by significantly improving the antioxidant potential i.e. antioxidative enzyme activities, antioxidants and free radical scavenging potential. Moreover, their synergistic interactions can further be employed to improve crop productivity in heavy metal polluted area. The findings could be used to further investigate the interdependence of the EBL and PAs at the molecular level, which will advance the field of phytohormonal interactions under stress.
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1 - University of Jammu, Department of Botany, Jammu, Jammu, NA, NA, India
Presentation Type: Oral Paper:Papers for Sections
Location: 551B/Convention Center
Date: Monday, August 2nd, 2010
Time: 3:15 PM