EFFECT OF EXOGENOUS POLYAMINES ON SCOTS PINE CALLUS IN-VITRO

Callus cultures were started from buds of mature Scots pines (Pinus sy lvestris L.) and exogenous putrescine, spermidine and spermine were ad ded to the growth medium in order to test their capacity to reduce bro wning and poor callus growth. Spermine (1 mmol/L) inhibited callus gro wth as measured in terms of dry weight. The effect of 1 mmol/L putresc ine was studied more closely using two types of growth medium (Krogstr up and modified Murashige and Skoog), and its influence on callus grow th and development was determined by measurements of dry weight, enzym e activities (arginine decarboxylase 4.1.1.19, ornithine decarboxylase 4.1.1.17 and phenylalanine ammonia-lyase 4.3.1.5), ethylene productio n, synthesis of soluble proteins and levels of free polyamines in call i. It was found to increase ethylene production in the callus, while i ts effect on protein synthesis, ADC and PAL activities depended on the growth medium, and changes in these react ions were seen in poorly gr owing callus in the form of decreases in ADC activity while PAL activi ty and the concentrations of two small polypeptides increased. High va lues of free putrescine were measured in calli in the presence of putr escine, but the concentrations of free spermidine and spermine did not clearly change. The results suggest that exogenous polyamines affect metabolism in pine callus but cannot prevent browning and deterioratio n.