than that in SNP-treated flower petals, particularly from day 0 to day 4 (Fig. 3b). For example, the ethylene production rate of SNP treatments was 66.4% lower than that of the control on day
6. Similarly, the inhibitory effects on ethylene production rate of NO were also largely depressed by simultaneous presence of cPTIO (Fig. 3b). These results suggest that NO could decrease ethylene output by depressing ACO activity during the senescence cut rose flowers.