Effect of drought stress on oxidative damage and antioxidant enzyme activity in melon seedlings

Authors : Musa KAVAS, Mehmet Cengiz BALOĞLU, Oya AKÇA, Fatma Selin KÖSE, Derya GÖKÇAY

Pages : 491-498

Doi:10.3906/biy-1210-55

View : 16 | Download : 7

Publication Date : 2013-12-01

Article Type : Research Paper

Abstract :Drought stress is one of the most serious environmental limitations affecting the growth and productivity of plants. In the current study, oxidative damage and antioxidant responses under polyethylene glycol insert ignore into journalissuearticles values(PEG);-induced osmotic stress were compared in 2 melon cultivars, Kırkağaç and Galia. Melon seedlings were subjected to PEG-6000 solutions of 2 different osmotic potentials, -0.2 MPa and -0.4 MPa. Various physiological parameters, malondialdehyde insert ignore into journalissuearticles values(MDA);, proline content, and antioxidant enzymes including catalase insert ignore into journalissuearticles values(CAT);, ascorbate peroxidase insert ignore into journalissuearticles values(APX);, and glutathione reductase insert ignore into journalissuearticles values(GR); were measured. A reduction in fresh and dry weights of shoot and root tissues was observed. Significant proline accumulation was detected with increasing osmotic potential for both cultivars. A significant rise in MDA was detected in Kırkağaç at -0.4 MPa osmotic potential. In Galia hydrogen peroxide insert ignore into journalissuearticles values(H2O2); content increased significantly as PEG concentration increased. CAT showed significantly increased activity only at -0.4 MPa osmotic potential in both cultivars. PEG-induced osmotic stress altered GR activity in both cultivars. These results suggest that insert ignore into journalissuearticles values(i); Galia is more tolerant than Kırkağaç, and insert ignore into journalissuearticles values(ii); drought tolerance in both cultivars might be closely related to an increase in capacity for antioxidant enzyme activity and the osmoprotective function of proline. Comparing these responses will help to identify drought tolerance mechanisms in melon cultivars.
Keywords : Key words Cucumis melo, drought stress, antioxidant enzymes, proline, malondialdehyde