Changes in Polyamine Titer in Etiolated Pea Seedlings Following Red Light Treatment1

The polyamines agmatine, cadaverine, putrescine, spermidine and spermine were measured by means of thin layer chromatography and high performance liquid chromatography in buds and in 5 mm long subapical sections of the 3rd internode of 6-day-old etiolated pea seedlings. The polyamine pattern of each organ was specific, relative quantities varying with age and growth. While agmatine, putrescine, spermidine and spermine were present in buds and in tissues of the 3rd internode, cadaverine was found in the 3rd internode only. Concentrations of spermidine and spermine were higher in the bud than in the 3rd internode, and the highest putrescine titer was found in the internode. Short exposure of etiolated seedlings to red light (5 min) increased bud development while inhibiting growth of the 3rd internode. In general, exposure to red light increased the titer of putrescine, agmatine and spermidine in the bud, whereas in the internode a reverse pattern was found, i.e., internodes of seedlings growing in the dark yielded higher titer of polyamines in general, and agmatine in particular. These results are particularly pronounced 18 hr after exposure to red light. A link between phytochrome-controlled growth and polyamine titer is suggested.