Effects of Gibberellic Acid and 6-Benzylaminopurine on Some Biochemical Parameters During Dark-Induced Leaf Senescence

In this study, effects of gibberellic acid (ga3) and 6-benzylaminopurine (bap) on some senescence parameters in detached leaves of tropaeolum majus l. (nasturtium) during dark-induced senescence were investigated. for this purpose, chlorophyll, protein, starch, hydrogen peroxide amounts, catalase and peroxidase activities of leaves kept in darkness after applying 10^-5 m ga_3 and 10^-5 m bap were determined. both the hormones reduced losses in chlorophyll and protein contents of leaves, but these treatments did not prevent rapid losses in starch amount under dark conditions. applications of bap and ga_3 increased significantly the catalase activity, decreased meaningfully peroxidase activity compared to the control group. the contents of hydrogen peroxide were markedly decreased in leaves applied by bap and ga_3. these results suggest that applications of bap and ga_3 found to be effective in senescence delay by changing the biochemical parameters of leaf senscence.