Transcriptome profiling reveals wound- and ethylene-signaling crosstalk during flower senescence in rose

Rose is one of the most important horticultural crops around the world, its ornamental and economic value mainly depends on the fully expansion and slow senescence of petals. Most of cut flowers are produced in developing countries, while their sales are mainly concentrated in developed countries and regions. Therefore, long-distance transportation from the production region to the point of sale is the mainstream channel for cut rose trade. However, long-distance transportation, usually in darkness, low temperature and without water, was easy to trigger the massive burst of exogenous ethylene production. Furthermore, stress-induced exogenous ethylene accelerated flower opening and senescence, and declined the vase life of cut rose by coupling with the mechanical damage during postharvest treatment. Avoid and reduce the negative effects of the long-distance transportation was crucial for maintain the postharvest quality of cut roses. Ethylene is required for the signaling transduction pathway of injury. However, the components involved in initial wound signal perception and transmission leading to the synthesis of ethylene is not clear. Meanwhile, the detailed molecular mechanisms of ethylene and wounding act together to regulate floral senescence remains poorly understood. In relation to this, identifying the initial signal of wounding, and signal crosstalk between wounding and ethylene pathway, were a crucial step in understanding early onset of floral senescence. Here, we monitored the status of flower opening and senescence day by day after wound, ethylene gas or dual-treatment both them, respectively. Furthermore, we employed RNA-seq technology to investigate the signal crosstalk involvement of wounding and ethylene pathway in the senescence process of harvested rose flowers. Many DEGs that encode two alternative pathways of protein degradation (proteases and ubiquitin-mediated protein modification) were found and acted function in coordination of the floral senescence program under ethylene and EW treatments, but no gene was screened from group 1, indicating that single wound was unbale to accelerate the floral senescence process of cut rose, unless dependent on ethylene signaling.