FREE POLYAMINES IN CICER-ARIETINUM SEEDS DURING THE ONSET OF GERMINATION

Alterations in the content of putrescine (Put), spermidine (Spd), spermine (Spm) and cadaverine (Cd) in the cotyledons and embryonic axis of Cicer arietinum during the first 24 hr of germination have been studied. The embryonic axis attached to the cotyledons contains a larger amount of these polyamines than the cotyledons themselves and larger amounts of Put, Spd and Spm than embryonic axes excised from the whole seeds before germination. Embryotomized cotyledons, on the other hand, show far greater polyamine levels than whole seeds, implying that the cotyledons are at least a partial source of polyamines for the embryonic axis. Nonetheless, Cd is greater in excised embryonic axes, suggesting some control over its synthesis in this organ by the cotyledons. In the embryonic axis, RNA synthesis coincides with an accumulation of Spm and Spd and that of DNA with an increase in Spd and Put. The greatest Spd:Put ratio occurs in the apical meristem of the embryonic axis, whilst Put accumulations are greatest in the elongation zone.