Influence of Environmental and Chemical Factors on Amitrole Metabolism in Excised Leaves

Abstract

Several factors were studied which influenced 3-amino-1,2,4-triazole (amitrole) metabolism in excised leaves of bean (Phaseolus vulgaris L., var. Red Kidney) and Canada thistle (Cirsium arvense (L.) Scop.) ecotypes. Amitrole metabolism in the leaves of both species held in the light was greater than in leaves held in the dark. Increasing the temperature from 15 C to 28 C also stimulated the rate of metabolism of amitrole. However, this effect was much less pronounced when the temperature was increased from 22 C to 28 C. Dipping the leaves in 10−2M ammonium thiocyanate reduced the metabolism of amitrole, whereas similar pre-treatment with 3.5 × 10−3M 6N-benzyladenine enhanced the metabolism of amitrole.