Enzyme activity and electrophoretic pattern of polyphenol oxidase in GA₃-and tannic acid-induced plants of Impatiens balsamina

The quantitative and qualitative changes caused by GA₃ and tannic acid (TA), singly and together on polyphenol oxidase activity in the stem and leaves of I. batsamina exposed to varying numbers of inductive and non-inductive photoperiodic cycles were studied. Polyphenol oxidase activity in the photoperceptive leaves increased significantly with a single treatment of plants with GA₃ or TA, or GA₃ + TA under both inductive and non-inductive photoperiods but not in the non-photoperceptive stem. A new isoenzyme of polyphenol oxidase (Rf 0.49) developed only under inductive conditions is suggestive of its involvement in floral bud initiation.

Floral buds were induced either by 8h photoperiods or by the application of GA₃ or TA or GA₃ + TA under non-inductive photoperiods.