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 recept or. Some of the antagonists have proven useful in scientific studies, and s ome promise to be commercially important in protecting against ethylene. Th e 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 comp ound. 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 str ained compounds (cyclopropenes) the half diffusion time is estimated to be 7-12 days; they block ethylene action during this time. The time of diffusi on from the receptor appears to be the major difference between compounds t hat block the receptor and those that are active. It is suggested that this time constant may be the controlling factor in ethylene action.