page_title: Ethylene as a plant hormone
hierarchical_section_title: Ethylene as a plant hormone
context_page_description: Ethylene is an unsaturated hydrocarbon gas acting naturally as a plant hormone. It acts at trace levels throughout the life of the plant by stimulating or regulating the ripening of fruit, the opening of flowers, the abscission of leaves and, in aquatic and semi-aquatic species, promoting the 'escape' from submergence by means of rapid elongation of stems or leaves. This escape response is particularly important in rice farming. Commercial fruit-ripening rooms use "catalytic generators" to make ethylene gas from a liquid supply of ethanol. Typically, a gassing level of 500 to 2,000 ppm is used, for 24 to 48 hours. Care must be taken to control carbon dioxide levels in ripening rooms when gassing, as high temperature ripening has been seen to produce CO₂ levels of 10% in 24 hours.
context_section_description: Ethylene (CH
  ₂=CH
  ₂) is an unsaturated hydrocarbon gas (alkene) acting naturally as a plant hormone. It acts at trace levels throughout the life of the plant by stimulating or regulating the ripening of fruit, the opening of flowers, the abscission (or shedding) of leaves and, in aquatic and semi-aquatic species, promoting the 'escape' from submergence by means of rapid elongation of stems or leaves. This escape response is particularly important in rice farming. Commercial fruit-ripening rooms use "catalytic generators" to make ethylene gas from a liquid supply of ethanol. Typically, a gassing level of 500 to 2,000 ppm is used, for 24 to 48 hours. Care must be taken to control carbon dioxide levels in ripening rooms when gassing, as high temperature ripening (20 °C; 68 °F) has been seen to produce CO₂ levels of 10% in 24 hours.
caption: An ethylene signal transduction pathway. Ethylene permeates the cell membrane and binds to a receptor on the endoplasmic reticulum. The receptor releases the repressed EIN2. This then activates a signal transduction pathway which activates regulatory genes that eventually trigger an ethylene response. The activated DNA is transcribed into mRNA which is then translated into a functional enzyme that is used for ethylene biosynthesis.