NO scavengers cPTIO or MB-1 significantly reduced the vase life and maximum flower diameter of cut flowers treated with 1-MCP. Similarly, NOS inhibitors l-NAME was able to attenuate the promotive effects of MB-1. However, treatments with NR inhibitor NaN3 did not reversed the increase of vase life induced by 1-MCP (Fig. 4). Thus, NOS- mediated NO generation in cut rose flowers may play an important role during its senescence regulated by ethylene.