Agmatine Metabolism and Hordatine Formation in Barley Seedlings

In the shoots of dark-grown barley seedlings coumaroylagmatineconcentration reaches a peak 3 d after germination; however,none could be detected 5 d after germination. Concentrationsof hordatines A, B and M show maxima 6 d after germination andthe concentrations decline to less than 50 per cent of the maximumby the 11th d. Putrescine, agmatine and spermidine peak respectively3,4 and 8 d after germination. Putrescine concentration declinesrapidly between the 8th and 9th d after germination. Agmatinecoumaroyl transferase (ACT) activity is greatest 3–4 dafter germination and activity is undetectable 5 d from germination.In the shoots of barley seedlings grown under diurnal illumination,hordatine M reached a peak 7 d after germination but no distinctpeaks could be found for hordatines A and B or coumaroylagmatine. Hordeum vulgare L., barley, coumaroylagmatine, hordatines, agmatine coumaroyltransferase, putrescine, spermidine