Effects of dicyclohexylamine on the changes in spermine levels in Hiproly barley callus after auxin withdrawal.

Abstract

Changes of the contents and biosynthetic rates of polyamines and enzyme activities involved in polyamine synthesis as aifected by dicyclohexylamine (DCHA) were examined in Hiproly barley callus. The incorporation of [l,4–14C]putrescine into spermidine increased rapidly after auxin withdrawal, while the incorporation of [l,4–14C]putrescine or [diaminobutane 1,4–14C]spermidine into spermine increased gently. The addition of DCHA suppressed the incorporation of [3,4-14C]methionine or [l,4–14C]putrescine into spermidine. In contrast, the incorporation of [3,4- 14C]methionine or [diaminobutane l,4–14C]spermidine into spermine increased in the callus by treatment of DCHA. The contents of spermine in the callus increased about 2-fold after treatment with 10 mm DCHA. The activity of spermidine synthase in the callus after auxin withdrawal increased rapidly. Inhibition of spermidine synthase by DCHA stimulated spermine synthesis and the activity of spermine synthase was elevated about 10-fold after treatment with ...