Ethylene is produced from the amino acid methionine, which by a series of reactions and by the action of the enzymes ACC synthase and ACC oxidase gives rise to the ethylene gas. Therefore, the production of ethylene is oxygen dependent, and under anaerobic conditions (absence of oxygen) the ethylene synthesis is completely repressed.

Its synthesis is stimulated by auxins, by wounds in the plant, ponding conditions or the beginning of the ripening of the fruits. However, abscisic acid inhibits its synthesis.

It intervenes mainly in the ripening of fruits, where ethylene is self-induced (that is, ethylene stimulates the production of more ethylene), accelerating and synchronizing the maturation process in the plant. Other actions of ethylene in the plant is its action as a regulator of the senescence and fall of flowers, petals and leaves. Its synthesis is also stimulated by stresses of biotic or abiotic origin. For example, situations of flooding or flooded land, produce anaerobiosis in the roots which stimulates the synthesis of ethylene in the stems, producing epinastia (curvature down the stem) and senescence. However, in semi-aquatic plants, such as rice, it promotes growth.