A Requirement for Polyamines during the Cell Division Phase of Radicle Emergence in Seeds of Acer saccharum

When stratified sugar maple seeds were germinated at 5C, celldivision did not contribute to radicle emergence or to earlygrowth of the embryonic axis. Putrescine, spermidine and sperminecontents remained low throughout stratification, but followinggermination their levels rose gradually for several days andthen entered a phase of rapid accumulation concurrent with initiationof rapid cell division. When inhibitors of putrescine and polyaminebiosynthesis were applied to newly germinated seeds, levelsof the amines and cell division were markedly reduced, but cellelongation, as evidenced by growth of hypocotyls, was not affected. ¹ Present address: Department of Chemistry and Biochemistry,University of Guelph, Guelph, Ontario, Canada N1G 2W1.