Ascorbate Oxidase Activity in Rice Shoot Apices during Panicle Initiation

Abstract

There was a decrease in the ascorbate oxidase activity in the shoot apices of Oryza sativa L. cv BAM 11, a photo-sensitive rice variety. Ascorbic acid content in the shoot apex increased and exogenous application of ascorbic acid resulted in an earliness in panicle initiation. Photoperiodic treatment promoted panicle initiation with an early and faster decline in ascorbate oxidase activity. Decline in the activity of ascorbate oxidase showed a negative correlation with the increase in ascorbic acid content.