The mutual regulation between DcEBF1/2 and DcEIL3-1 is involved in ethylene induced petal senescence in carnation (Dianthus caryophyllus L.).

Carnation (Dianthus caryophyllus L.) is a respiratory climacteric flower, which is one of the most important cut flowers extremely sensitive to plant hormone ethylene. Ethylene signaling core transcription factor DcEIL3-1 plays a key role in ethylene induced petal senescence in carnation. However, how dose DcEIL3-1 be regulated in carnation petal senescence process is still not clear. Here, we screened out two EBF (EIN3 Binding F-box) genes, DcEBF1 and DcEBF2, which showed quickly elevation by ethylene treatment according to the ethylene induced carnation petal senescence transcriptome. Silencing of DcEBF1 and DcEBF2 accelerated while overexpression of DcEBF1 and DcEBF2 delayed ethylene induced petal senescence in carnation through influencing DcEIL3-1 downstream target genes but not DcEIL3-1 itself. Further, DcEBF1 and DcEBF2 interact with DcEIL3-1 to degrade DcEIL3-1 through ubiquitination pathway in vitro and in vivo. Last but not least, DcEIL3-1 binds to the promoter regions of DcEBF1 and DcEBF2 to activate their expression. In conclusion, this study revealed the mutual regulation between DcEBF1/2 and DcEIL3-1 during ethylene induced petal senescence in carnation, which not only expanding our understanding about ethylene signal regulation network in carnation petal senescence process but also provide potential targets to breed cultivar of long-lived cut carnation.