Age-related changes in catalase and peroxidase activities in the excised leaves of Eleusine coracana Gaertin. cv PR 202 during senescence.

Changes in the activities of the enzymes catalase and peroxidase were studied in the excised leaves of ragi (Eleusine coracana Gaertn. cv PR 202) plants belonging to different ages. Catalase exhibited a positive and peroxidase a negative correlation with the changes in chlorophyll. Catalase and peroxidase were negatively correlated with each other. Peroxidase exhibited an age-related drift in its activity. Kinetin could maintain the levels of chlorophyll and catalase, and also caused an increase in peroxidase activity. Both indoleacetic acid and gibberellic acid had no effect on the changes of chlorophyll but increased peroxidase activity. Catalase levels were maintained by indoleacetic acid but gibberellic acid had no effect on this enzyme.