Effects of tetcyclacis on growth and on sterol and sapogenin content in fenugreek

Autor: A. Rahier, M. Taton, Yves Sauvaire, Claude Cerdon
Rok vydání: 1995
Předmět:
Zdroj: Journal of Plant Growth Regulation. 14:15-22
ISSN: 1435-8107
0721-7595
DOI: 10.1007/bf00212641
Popis: Tetcyclacis, a norbornanodiazetine plant growth retardant, used at 10 mg · L−1 (36 μm), caused greater growth inhibition in the shoots of fenugreek (Trigonella foenum-graecum L.) seedlings (60%) than in the roots (30%), compared with control. This greater retardation was reversed by a supplement of gibberellin (200 mg · L−1). The total sterol composition of control and treated seedlings was analyzed and quantified. In the roots especially, treatment of seedlings with tetcyclacis resulted in a modification of the sterol profile, leading to an accumulation of 14α-methyl sterols, presumably as a consequence of the inhibition of cytochrome P-450-dependent obtusifoliol 14α-demethylase. In addition, tetcyclacis caused a significant increase in the cholesterol content of the roots: 38.1% of total sterols against 3.7% in the control roots. However, tetcyclacis was shown to be an ineffective inhibitor of the S-adenosyl-l-methionine (Adomet): cycloartenol-C24-methyltransferase (EC 2.1.1.41) in fenugreek microsomes indicating that cholesterol accumulation does not result from the inhibition of the sterol side chain-alkylating enzyme. Moreover, this accumulation was shown to be concomitant with a significant decrease of the sapogenin content in the treated roots. This last result is discussed with respect to the current proposed pathway by which cholesterol is metabolized to saponins.
Databáze: OpenAIRE
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