Inhibition by polyamines of macromolecular synthesis and its implication for ethylene production and senescence processes.

Applied diamines and polyamines inhibited the incorporation of radioactively labeled leucine and uridine into trichloroacetic acid-insoluble material in apple (Malus domestica Borkh, cv Golden Delicious) fruit tissue. The inhibitory effect was in general more pronounced with the higher molecular weight amines. Putrescine at 5 millimolar inhibited leucine incorporation by 37% and uridine by 44%. Spermidine and spermine at the same concentration inhibited uridine incorporation by 60%. The polyamines at concentrations between 0.1 and 1.0 millimolar inhibited leucine incorporation by 55 to 90%. The inhibitory effect of 0.1 to 10 millimolar polyamines on dark- and wound-induced senescence or ethylene production, is discussed in the light of interference with macromolecular synthesis.