Exogenous treatment with sucrose and l-phenylalanine enhance scent emission from cut carnation flowers but their effects are different

In <i>Dianthus caryophyllus</i> L. (carnation), floral scent emission declines more rapidly after cutting than when plants remain in the ground. Treatment using exogenous sucrose or l-phenylalanine (Phe) increases scent emission from cut flowers of some ornamental plants; however, carnations have not been studied in this context. This study aimed to evaluate the effects of exogenous sucrose and Phe on scent emission in cut carnation flowers. Sucrose, a substrate for benzenoids/phenylpropanoids (BPs), terpenoids, and fatty acid derivatives, increased emissions of all these compounds. However, Phe, a BP precursor, increased BP emissions only selectively. In addition to acting as scent biosynthetic substrates, both inhibited senescence, delaying β-caryophyllene increase and aligning daily scent composition more closely with that of intact flowers. Thus, the physiological effects of sucrose and Phe also contribute to scent regulation. These compounds show potential as scent-preserving agents for cut carnations; however, the scent enhancement effects in more cultivars and Phe-induced leaf yellowing must be confirmed for practical use.