+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Enzymes of N-methylputrescine biosynthesis in relation to hyoscyamine formation in transformed root cultures of Datura stramonium and Atropa belladonna



Enzymes of N-methylputrescine biosynthesis in relation to hyoscyamine formation in transformed root cultures of Datura stramonium and Atropa belladonna



Planta 182(1): 136-141



The activities of enzymes related to the biosynthesis of N-methylputrescine, a precursor of the alkaloid hyoscyamine, have been measured in root cultures of Datura stramonium L. and Atropa belladonna L. transformed with Agrobacterium rhizogenes. Ornithine δ-Nmethyltransferase and δ-N-methylornithine decafboxylase were undetectable, indicating that δ-N-methylornithine is an unlikely intermediate in the formation of N-methylputrescine. The activity of putrescine-N-methyltransferase (EC 2.1.1.53) was comparable to, or greater than, that of arginine decarboxylase (EC 4.1.1.19) or ornithine decarboxylase (EC 4.1.1.17). Radiolabel from DL-[5-(14)C]ornithine, L-[U-(14)C]arginine, [U-(14)C]agmaine and [1,4-(14)C]putrescine was incorporated into hyosyamine by Datura cultures. Hyoscyamine production by Datura cultures was substantially inhibited by the arginine-decarboxylase inhibitor, DL-α-difluoromethylarginine, but not by the corresponding ornithine-decarboxylase inhibitor, DL-α-difluoromethylornithine. Together with the demonstration that label was incorporated from [U-(14)C]agmatine, this indicates clearly that arginine is metabolised to hyoscyamine at least in part via decarboxylation to agmatine, even though a high activity of arginase (EC 3.5.3.1) was measurable under optimal conditions. The effect of unlabelled putrescine in diminishing the incorporation into hyoscyamine of label from DL-[ 5-(14)C] ornithine and L-[U-(14)C] arginine does not lend support to the theory that ornithine is metabolised via a bound, asymmetric putrescine intermediate.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 053002524

Download citation: RISBibTeXText

PMID: 24197009

DOI: 10.2307/23380392


Related references

Early stages of hyoscyamine biosynthesis in transformed root cultures of Datura stramonium and Atropa belladonna. Planta medica 56(6): 606, 1990

Growth and the uptake of sucrose and mineral ions by transformed root cultures of Datura stramonium, Datura Candida x aurea, Datura wrightii, Hyoscyamus muticus and Atropa belladonna. Planta Medica 61(4): 345-350, 1995

Studies on the synthesis of hyoscyamine in Atropa belladonna L. and Datura stramonium L. Biochemical Journal 37(6): 717-722, 1943

Tropinone reductase in root cultures of Hyoscyamus niger, Atropa belladonna and Datura stramonium. Planta Medica 56(6): 499, 1990

Two tropinone reducing enzymes from Datura stramonium transformed root cultures. Phytochemistry 31(4): 1135-1138, 1992

Studies on the biosynthesis of tropane alkaloids in Datura stramonium L. transformed root cultures. Planta 83(2): 196-201, 1991

Elicitation of tropane alkaloid biosynthesis in transformed root cultures of Datura stramonium. Phytochemistry 50(1): 53-56, 1999

Studies on the biosynthesis of tropane alkaloids by Datura stramonium L. transformed root cultures: 3. The relationship between morphological integrity and alkaloid biosynthesis. Planta 185(3): 385-390, 1991

Studies on the biosynthesis of tropane alkaloids by Datura stramonium L. transformed root cultures : 3. The relationship between morphological integrity and alkaloid biosynthesis. Planta 185(3): 385-390, 1991

Studies on the biosynthesis of tropane alkaloids in Datura stramonium L. transformed root cultures: 2. On the relative contributions of L-arginine and L-ornithine to the formation of the tropane ring. Planta 183(2): 196-201, 1991

Studies on the biosynthesis of tropane alkaloids in Datura stramonium L. transformed root cultures : 2. On the relative contributions of L-arginine and L-ornithine to the formation of the tropane ring. Planta 183(2): 196-201, 1991

Production of Hyoscyamine by 'Hairy Root' Cultures of Datura stramonium. Planta Medica 53(5): 474-478, 1987

Hyoscyamine biosynthesis in Datura stramonium hairy root in vitro systems with different ploidy levels. Applied Biochemistry and Biotechnology 157(2): 210-225, 2009

Effects of Ri T-DNA from Agrobacterium rhizogenes on growth and hyoscyamine production in Datura stramonium root cultures. Botanica Acta 109(2): 133-138, 1996

Studies on the biosynthesis of tropane alkaloids in Datura stramonium L. transformed root cultures : 1. The kinetics of alkaloid production and the influence of feeding intermediate metabolites. Planta 183(2): 185-195, 1991