Ethylene and Carbon Dioxide: Mediation of Hypocotyl Hook-Opening Response

See allHide authors and affiliations

Science  19 May 1967:
Vol. 156, Issue 3777, pp. 958-959
DOI: 10.1126/science.156.3777.958


Ethylene at low concentrations inhibits the light-induced opening of the bean hypocotyl hook; auxin inhibits the opening by inducing production of ethylene. Light causes a decrease in ethylene production and an increase in the production of carbon dioxide. Hook opening appears to be a response in which ethylene serves as a natural growth regulator and in which carbon dioxide may be involved also as a growth regulator through its antagonism of the action of ethylene.