Advances in the Regulation of Carnation Flower Senescence: Hormonal Control and Emerging Molecular Layers

Carnation (Dianthus caryophyllus L.) is a globally important cut flower, and its postharvest longevity is a key determinant of commercial value. Flower senescence in carnation is a genetically programmed yet environmentally modulated process involving coordinated physiological, biochemical, hormonal, and molecular changes. This review synthesizes recent advances in the regulation of carnation petal senescence, with a particular focus on ethylene (ETH)-dependent signaling, hormonal crosstalk, metabolic regulation, and emerging molecular control layers. ETH acts as the central regulator of senescence, interacting with abscisic acid, cytokinins, gibberellins, and auxins to control the timing and progression of petal aging. Recent studies have identified key regulatory genes, including DcACS1, DcACO1, DcEIL3-1, DcWRKY75, DcNAP1/2, DcATX1, and m6A methylation-related factors, revealing multilayered control of senescence progression. Emerging evidence further demonstrates that RNA m6A modification links ETH signaling with antioxidant capacity and metabolic homeostasis. We propose an integrated regulatory network model that connects hormonal crosstalk, environmental cues, transcriptional control, and post-transcriptional regulation. This updated framework provides mechanistic insights into developing targeted postharvest treatments and breeding strategies to extend vase life of cut carnation flowers.