Abstract
Leaf disks (1.0 cm in diameter) of tender-green mustard (Brassica campestrisL. var. perviridisL. H. Bailey) grown under controlled environmental condition were incubated on water in the light (13, 000 lux) or in the dark at 25°C for 4 days.
During incubation L-ascorbic acid content of the leaf disks rapidly increased in the light and decreased in the dark. Peroxidase activity increased in the dark during incubation, but the increase of activity was considerably suppressed in the light.
On the other hand, the fall in levels of chlorophyll and protein during incubation was observed in both light and darkness. The result indicates that senescence of leaf disks proceeds during incubation.
These suggest that the change in peroxidase activity during senescence of leaf disks of tender-green mustard is closely related to L-ascorbic acid content affected by light.
The differences between disks cut from old and young leaves were also studied about the changes in the contents of L-ascorbic acid, chlorophyll, protein and peroxidase activity during incubation of the leaf disks, but there was no significant difference in both disks.
