Ethylene

Ethylene is a hydrocarbon plant hormone that comes from the methionyl moiety of S-adenosylmethionine. Ethylene stimulates fruit ripening and the aging of flowers, and it inhibits seedling growth. It also redirects auxin transport (another plant hormone) to promote transverse, rather than longitudinal, growth of plants.

See also: Plant Hormones, Figure 23.25

INTERNET LINK: Plant Hormones