Changes in enzyme activities related to hydrogen peroxide metabolism during senescence of wheat plant

During reproductive development the activity of catalase decreased in the three upper-most leaves of wheat plant (Triticum aestivum cv. Sonalika), but the peroxidase activity increased up to the grain maturation stage. Benzyladenine (BA, 4.4 x 10⁻⁴M) treatment prevented the fall in catalase activity, whereas abscisic acid (ABA, 7.5 X 10⁻⁵M) treatment raised the decline of this enzyme. BA treatment enhanced the activity of peroxidase in all the three leaves, while ABA treatment prevented the rise of this enzyme activity. These two enzymes, associated with hydrogen peroxide breakdown, are opposite to each other in wheat leaves during senescence at the reproductive development.