ETHYLENE AND ACC: MOBILE WILTING FACTORS IN FLOWERS.

Ernst J. Woltering, H. Overbeek, F. Harren
In Cymbidium flowers, emasculation leads to a transient increase in ethylene production. In intact flowers, the major part of the ethylene produced is derived from the lip and petals, whereas an increase in the level of l-aminocyclopropane-1-carboxylic acid (ACC) is only observed in the central column (gynostemium). In petals, excised at different times after emasculation, the production of ethylene ceases immediately after excision. Application of ACC to the top of the central column leads to the production of ethylene by the petals. These results indicate that both endogenously produced, as well as applied, ACC is translocated within the flower. Treatment of the central column with ethylene or ethephon leads to an ethylene response in the lip and petals, while no increase in ACC in any of the flower parts is observed. This indicates that ethylene, too, is translocated within these flowers.

In isolated carnation petals, wilting of the upper part is dependent on the presence of the basal part. Mor et al. (Physiol. Plant. 65:196–202, 1985) showed that ACC, which is produced in the basal part, is translocated to the upper part. Treatment with ACC induces wilting in intact petals but is without effect in excised upper petal parts. This indicates that wilting in upper parts requires an additional factor which is derived from the basal part. Treatment of excised upper parts with a combination of ACC and ethephon or ACC and ethylene restores the normal wilting response. These results, therefore, indicate that both ACC and ethylene are translocated from the basal part to the upper part of the petal.

The role of ACC and ethylene and the possible involvement of other mobile wilting factors in the coordination of flower senescence is discussed.

Woltering, Ernst J., Overbeek, H. and Harren, F. (1991). ETHYLENE AND ACC: MOBILE WILTING FACTORS IN FLOWERS.. Acta Hortic. 298, 47-60
DOI: 10.17660/ActaHortic.1991.298.4
https://doi.org/10.17660/ActaHortic.1991.298.4

Acta Horticulturae