Studies on plant growth-regulating substances. LIV. Factors affecting the production of active growth substances from structurally related amines in plants

A diamine oxidase enzyme has been isolated from pea epicotyls and purified. The in vitro rates at which a number of amines, structurally related to plant growth substances, are oxidised by this enzyme have been measured. These rates when considered together with the growth regulating activity of the acid ultimately produced, enable an assessment of the activity of the amine as a hormone-type herbicide to be made.