Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 1, 2004
Publication Date: December 1, 2004
Citation: Baldwin, E.A. 2004. Ethylene and postharvest commodities. Hortscience. 39(7):1538-1540. Interpretive Summary: This paper is a review of the plant hormone ethylene. Ethylene is a gas produced by both combustion engines and plants. In plants the gas acts as a hormone and is responsible for inducing fruits and vegetables to ripen, soften, color, and produce aroma compounds. It is used commercially to ripen bananas and tomatoes that are harvested immature. This gaseous plant hormone also causes fruit and leaves to fall off trees, a process known as abscission. On the other hand, ethylene can have some detrimental effects on fresh produce and flowers, such as inducing bitter compounds in carrots, toughening of asparagus stems, senescence of flowers, and a general shortening of fruit and flower shelf life after harvest. Finally, ethylene can either enhance or inhibit decay of fruit tissue by certain pathogens.
Technical Abstract: This paper is a review of the plant hormone ethylene, a simple two carbon molecule. This hormone is biologically active at low concentrations (part per billion to part per million range). Since it is a gas, it is easily transported long distances via diffusion from site of synthesis within the plant. Synthesis of ethylene is from the plant amino acid methionine to S-adenosymethionine (ACC) to ethylene via enzymes ACC synthase and ACC oxidase. To have an effect, ethylene must bind to a receptor thought to reside in a membrane. Genes for the two rate limiting enzymes in the ethylene biosynthesis pathway and the receptor protein have been down regulated, producing plants that produce little if any ethylene. Ethylene stimulates ripening of climacteric fruits and color changes in both climacteric and non-climacteric fruits and vegetables. It is used commercially to ripen fruits like bananas and tomatoes and as an abscission agent. Ethylene can also cause deterioration of fresh produce and flowers, thus shortening their shelf-life.