Levels of ACC in Various Floral Portions During Aging of Cut Carnations

Abstract Studies were conducted to determine the involvement of ACC movement from extrapetal portions with initiation of petal senescence. During early senescence, ACC in all portions except the calyx displayed transient increases in levels of ACC. The largest increase in ACC specific concentration occurred in the receptacle. Removal of petals at harvest resulted in accumulation of ACC in the ovary and receptacle. [ 14 C]ACC applied to the styles moved to the petals within 24 hr, but during this time, very little 14 C was found in the receptacle. Although the major rise in ACC occurred in styles, ovary, receptacle, and petals between days 6 and 10 of aging, a secondary transient peak of ACC was always observed between days 2 and 4 only in the receptacle. It is suggested that the receptacle may contribute significantly to the initiation of petal senescence by acting as a source of ACC. Chemical names used: 1-aminocyclopropane-1-carboxylic acid (ACC).