Effects of polyamine biosynthesis inhibitors on S-adenosylmethionine synthetase and S-adenosylmethionine decarboxylase activities in carrot cell cultures
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Plant Physiology and Biochemistry. 29: 231-237.
Changes in the activites of S-adcnosylmethionine (SAM) synthetase (methionine adenosyltransferase, EC 18.104.22.168.) and SAM decarboxylase (EC 22.214.171.124) were studied in carrot (Daucus carota) cell cultures in response to 2,4-dichlorophenoxyacetic acid (2,4-D) and several inhibitors of polyamine biosynthesis. Activity of SAM synthetase increased significantly during the first 5 days of culture under all conditions, maximum activity being observed in thc presence of 2,4-D. DL-α-Difluoromethylarginine (DFMA), I,L-α-difluoroinethylornithine (DFMO) and cyclohexylammonium sulfatc (CHAS) had little effect on the activity of this enzyme. The enzyme activity was lower than the controls in the presence of methylglyoxal bis(guany1hydrazone) (MGBG). The activity of SAM dccarboxylasc, which showed a peak on day 2 in all treatments, was lowered by 2,4-D, DFMA, MGBG and CHAS. The results are consistent with published reports on the effects of these inhibitors on the cellular levels of polyainines.
KeywordsCyclohexylaminonium sulfate, 2,4-dichlorophcnoxyacetic acid, difluoromethylarginine, difluoromethylornithine,methylglyoxal bis(guanylhydrazone)
Minocha, S.C.; Minocha, R.; Komamine, A. 1991. Effects of polyamine biosynthesis inhibitors on S-adenosylmethionine synthetase and S-adenosylmethionine decarboxylase activities in carrot cell cultures. Plant Physiology and Biochemistry. 29: 231-237.