INVOLVEMENT OF AUXIN IN THE CONTROL OF SENESCENCE IN PETUNIA FLOWERS.

Auxin stimulated ethylene production in cut petunia flowers. The stem and sepals responded to auxin treatment with higher ethylene production compared with the corolla. Auxin was found to be metabolized more intensively in the corolla compared with the stem and sepals. Since as flowers age, the stem, sepals and the lower parts of the corolla seem to retain the level of auxin found in young flowers, the possibility of auxin originated in the stem regulating senescence of the corolla is suggested.