Alkaloids Derived from Ornithine, Lysine, and Nicotinic Acid

Leete, Edward

doi:10.1007/978-3-642-67360-3_4

Cited by 21 publications

(8 citation statements)

References 141 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the past, ODC rather than ADC activity has been related to the biosynthesis of nicotine (15) and, in fact, pyrrolidine alkaloids have been classified asornithine-derived compounds (10). We have found that ADC activity is much higher than ODC in callus grown on all media and that changes in ADC activity, but not ODC, correspond to increased alkaloid levels in the callus.…”

Section: Discussionmentioning

confidence: 61%

“…However, relatively little is known about their role in secondary plant metabolism. Putrescine is a precursor not only of PAs (7), but also of parts of important alkaloids such as the pyrrolidine rings of tobacco alkaloids (nicotine and nomicotine), tropane alkaloids (hyoscyamine, hyoscine, and meteloidine), pyrrolizidine alkaloids (retronecine), and possibly phenanthroindolizidines (tylophorine) (10). The putrescine-derived PAs (spermidine, homospermidine, and spermine) may be conjugated to cinnamic acids or to fatty acids, giving rise to other more complex alkaloids (18).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Correlation between Polyamines and Pyrrolidine Alkaloids in Developing Tobacco Callus

Tiburcio¹,

Kaur‐Sawhney²,

Ingersoll³

et al. 1985

Plant Physiol.

109

View full text Add to dashboard Cite

Since the diamine putrescine can be metabolized into the pyrrolidine ring of tobacco alkaloids as well as into the higher polyamines, we have investigated the quantitative relationship between putrescine and these metabolites in tobacco callus cultured in vitro. We measured levels of free and conjupted putrescine and spermidine, and pyrrolidine alkaloids, as well as activities of the putrescine-biosynthetic enzymes arginine and ornithine decarboxylase. In callus grown on high (11.5 micromolar) anaphthalene acetic acid, suboptimal for alkaloid biosynthesis, putrescine and spermidine conjugates were the main putrescine derivatives, while in callus grown on low (1.5 micromolar) a-naphthalene acetic acid, optimal for alkaloid formation, nornicotine and nicotine were the main putrescine derivatives. During callus development, a significant negative correlation was found between levels of perchloric acid-soluble putrescine conjugates and pyrrolidine alkaloids. The results suggest that bound putrescine can act as a pool for pyrrolidine alkaloid formation in systems where alkaloid biosynthesis is active. In addition, changes in arginine decarboxylase activity corresponding to increased alkaloid levels suggest a role for this enzyme in the overall biosynthesis of pyrrolidine alkaloids.Polyamines and their biosynthetic enzymes ADC3 (EC 4.1.1.19) and ODC (EC 4.1.1.17) may play an important role in many aspects of plant development including growth, differentiation, senescence, and response to stress (7). However, relatively little is known about their role in secondary plant metabolism. Putrescine is a precursor not only of PAs (7), but also of parts of important alkaloids such as the pyrrolidine rings of tobacco alkaloids (nicotine and nomicotine), tropane alkaloids (hyoscyamine, hyoscine, and meteloidine), pyrrolizidine alkaloids (retronecine), and possibly phenanthroindolizidines (tylophorine) (10). The putrescine-derived PAs (spermidine, homospermidine, and spermine) may be conjugated to cinnamic acids or to fatty acids, giving rise to other more complex alkaloids (18).PAs are present in the plant cell in both free and conjugated forms (19,20 been correlated with the onset of reproduction (4) and virus resistance (12), but not with alkaloid biosynthesis.Several publications support the view that auxin levels are involved in the regulation of nicotine production by tobacco callus cultures (22) and root cultures (21) as well as in the intact tobacco plant (25). Recently, we found (23) that the alkaloid level increased dramatically when tobacco callus grown on 11.5 ,gM NAA (suboptimal for alkaloid biosynthesis) was transferred to a medium containing 1.5 ;tM NAA (optimal for alkaloid biosynthesis). In the present study, we have used this experimental approach to investigate the relation between PAs (free and conjugated) and pyrrolidine alkaloids in tissues where alkaloid biosynthesis is active. The activities of ODC and ADC in relation to pyrrolidine alkaloid formation were also investigated.MATERIALS AND METHODS P...

show abstract

Section: Discussionmentioning

confidence: 61%

mentioning

confidence: 99%

Correlation between Polyamines and Pyrrolidine Alkaloids in Developing Tobacco Callus

Tiburcio¹,

Kaur‐Sawhney²,

Ingersoll³

et al. 1985

Plant Physiol.

109

View full text Add to dashboard Cite

show abstract

“…However, all three NsPMT genes are expressed in the same cell types and are activated similarly by jasmonate treatment. A possible explanation for their similarity in expression patterns is that nicotine and its immediate metabolic products are the only known compounds derived from the linear biosynthetic pathway in which PMT is involved (Leete 1980), and that consequentially there is no advantage in controlling PMT gene family members differentially. In this regard, the gene duplication events, which presumably involved the ancestral PMT gene of N. sylvestris, might have been fixed by chance.…”

Section: Structure Of Nspmt Genesmentioning

confidence: 99%

Jasmonate Induction of Putrescine N-Methyltransferase Genes in the Root of Nicotiana sylvestris

Shoji

Yamada

Hashimoto

2000

Plant and Cell Physiology

174

126

View full text Add to dashboard Cite

;Nicotine alkaloids are synthesized in the root of Nicotiana species, and their synthesis increases after insect attack, wounding and jasmonate treatment of the leaf. Putrescine N-methyltransferase (PMT) catalyzes the first committed step in nicotine biosynthesis. The expression patterns of the three Nicotiana sylvestris PMT genes (NsPMT1, NsPMT2, and NsPMT3) are reported in this study. Transcripts of the NsPMT genes were detected only in the root, and were up-regulated by methyl jasmonate treatment. When the 5¢-flanking regions of NsPMT1, NsPMT2, and NsPMT3 were fused independently to b-glucuronidase reporter gene and introduced into N. sylvestris by Agrobacterium-mediated transformation, all introduced transgenes were expressed in the cortex, endodermis, and xylem in the root, as well as upregulated by methyl jasmonate treatment. These qualitatively similar patterns of expression for the NsPMT genes are achieved with only 0.25 kb of their conserved 5¢-flanking regions, which contained no known jasmonate-responsive elements.

show abstract

“…Nicotine is synthesized in the tobacco root from ornithine andlor arginine by way of putrescine (Leete, 1980). Putrescine is either metabolized to higher polyamines, such as spermidine and spermine, or conjugated with cinnamic acid derivatives or fatty acids in all higher plants (Smith, 1981); it is also converted to N-methylputrescine in plants that produce nicotine or tropane alkaloids (Figure 1).…”

Section: Introductionmentioning

confidence: 99%

Gene expression in tobacco low-nicotine mutants.

et al. 1994

View full text Add to dashboard Cite

Two nuclear genes, Nicl and Nic2, regulate nicotine levels in tobacco. nicl and nic2 are semidominant mutations in Burley 21 that reduce leaf nicotine levels and the activities of multiple enzymes in the nicotine pathway and simultaneously increase polyamine levels in cultured roots. Cultured roots homozygous for both mutations were used to isolate two cDNAs by subtraction hybridization; the transcript levels of these two cDNAs were much lower in the mutant roots than in the wild-type roots. The A411 gene encodes a 41-kD protein with considerable homology to mammalian spermidine synthase, whereas the A622 gene encodes a 35-kD protein with high homology to isoflavone reductase. When these genes were expressed in Escherichia coli, A411 had no spermidine synthase activity but did show putrescine N-methyltransferase activity, which is the first enzyme committed to the nicotine biosynthetic pathway, and A622 did not show isoflavone reductase activity. Both the methyltransferase and A622 genes are predominantly expressed in the root, and their expression levels in cultured roots are coordinately decreased by the nic mutations in the order of wild type > nic2 > nicl > nicl nic2. Removal of tobacco flower heads and young leaves rapidly and coordinately induced both genes in the root. Further, exogenous supply of auxin down-regulated both genes in cultured tobacco roots. These results suggest that N i c l and Nic2 are regulatory genes for nicotine biosynthesis.

show abstract

Alkaloids Derived from Ornithine, Lysine, and Nicotinic Acid

Cited by 21 publications

References 141 publications

Correlation between Polyamines and Pyrrolidine Alkaloids in Developing Tobacco Callus

Correlation between Polyamines and Pyrrolidine Alkaloids in Developing Tobacco Callus

Jasmonate Induction of Putrescine N-Methyltransferase Genes in the Root of Nicotiana sylvestris

Gene expression in tobacco low-nicotine mutants.

Contact Info

Product

Resources

About