ISSN:
1399-3054
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Biondi, S., Torrigiani, P., Sansovini, A. and Bagni, N. 1988. Inhibition of polyamine biosynthesis by dicyclohexylamine in cultured cotyledons of Pinus radiata. - Physiol. Plant. 72: 471–476.The effect of 1 mAf dicyclohexylamine (DCHA) on the synthesis of spermidine and spermine was examined in excised cotyledons of radiata pine (Pinus radiata D. Don) cultured under shoot-forming (with cytokinin) and non-shoot-forming (minus cytokinin) conditions by incubation with [14C]-putrescine. In control cotyledons incorporation into spermidine showed a peak at day 2 in the presence and at day 5 in the absence of N6-benzyldenine (BA). DCHA-treated cotyledons gave the same labeling pattern, both in the presence and absence of benzyladenine, with a much smaller peak at day 2. The incorporation into spermidine and spermine was insignificant at day 5 and later. The total radioactivity in the trichloroacetic acid supernatant indicated that precursor uptake was strongly reduced by the drug. In addition, the percentage label found in the benzene phase and combined in the 3 polyamines was lower in DCHA-treated cotyledons. Thus, treatment with DCHA not only inhibited the conversion from putrescine to spermidine and spermine, but also reduced its conversion to other benzene-extractable compounds. S-Adenosylmethionine decarboxylase (SAMDC, EC 4.1.1.50) activity, which furnishes the propylamine group to spermidine and spermine synthases (EC 2.5.1.16 and EC 2.5.1.-), was not significantly affected by DCHA and appeared to be independent of the spermidine and spermine synthase reactions, suggesting that spermine synthesis decreased as a result of substrate depletion. The correlation between morphological development and polyamine biosynthesis is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1399-3054.1988.tb09153.x
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