Relation between Mineral Deficiency and Amine Synthesis in Barley

Abstract

IT has been shown that when potassium is deficient, barley—like other species—accumulates the amines putrescine and agmatine^1,2, which are derived from arginine. The product of decarboxylation, agmatine, is converted to putrescine with the intermediate formation of N-carbamylputrescine. Furthermore, when phosphorus is deficient, barley has an increased agmatine content, but there is no corresponding increase in putrescine³. In the plants deficient in potassium the production of agmatine and putrescine is accompanied by an increase in the activity of the enzymes, arginine carboxy-lyase and N-carbamylputrescine amidohydrolase^4,5. It was of interest, therefore, to compare the activities of these two enzymes and the production of amines when phosphorus and potassium were deficient, and also to investigate the concentrations of agmatine and putrescine when some other essential elements were deficient.