The Metabolism of Labeled Amitrole in Plants

Abstract
The metabolism of 3-amino-I,2,4-tri-azole (amitrole) in bean (Phaseotus vulgaris L., cv. "Black Valentine") corn (Zea may L., cv. "Batam Cross"), and sugar beet (Beta sacchari-fera L.) leaves was studied with both C14 and tritium-labeled amitrole. Insignificant amounts of C14 were recovered in the respired CO2 from plants given amitrole-5-C14. The metabolic conversion of amitrole in leaves was exponential and can be expressed by an equation for a 1st order reaction. The half-time of amitrole in sugar beet, corn, and bean leaves were 18.7, 28.0, and 23.2 hr, respectively. Radioactivity from amitrole-5-Cl4 was in extracts or nucleic acids, proteins, and other plant constituents. Largest amounts of radioactivity were recovered as alcohol soluble metabolites. Experiments with (amitrole H3) and (amitrole-5-C14) showed the position of hydrogen substitution in each alcohol soluble metabolite.