Ethylene, the Gaseous Plant Hormone

Abstract
Ethylene is a plant hormone that regulates many aspects of plant growth and development ranging from seed germination to organ senescence. Plants produce ethylene from methionine via S-adenosylmethionine and 1-aminocyclopropane-1-carboxylic acid (ACC). The synthesis of ACC appears to be the main site of control of ethylene synthesis. Little is known about the site and mode of action of ethylene. Based on studies of the action of ethylene and its analogs, it is thought that ethylene binds to a metal-containing receptor before it exerts its physiological effects. An ethylene-binding site has been isolated.