Compounds controlling the ethylene receptor

Many organic compounds interact with the ethylene receptor and diffuse free after different periods of time. Some are agonists and mimic ethylene, and some are antagonists, which prevent ethylene action by blocking the receptor. Some of the antagonists have proven useful in scientific studies, and some promise to be commercially important in protecting against ethylene. The times that different compounds remain bound may be important clues to how ethylene transmits its signal to the signal transduction pathway. Ethylene diffuses from the site with a t 1/2 of 2–10 minutes and is an active compound. For 2,5-Norbornadiene (2,5-NBD) and some other strained olefins that block ethylene action, the half diffusion time is 3–6 h. For other more strained compounds (cyclopropenes) the half diffusion time is estimated to be 7–12 days; they block ethylene action during this time. The time of diffusion from the receptor appears to be the major difference between compounds that block the receptor and those that are active. It is suggested that this time constant may be the controlling factor in ethylene action.