Effect of agmatine on putrescine formation in tobacco plants

Incorporation of L-arginine-U-14C, fed to leaf disks of tobacco plants, into putrescine decreased about 70% in the presence of agmatine, but that of L-ornithine-U-14C decreased only slightly. These results indicate that putrescine is synthesized from arginine via agmatine, but is also synthesized from ornithine without passing through arginine and agmatine.