Correlation between Polyamines and Pyrrolidine Alkaloids in Developing Tobacco Callus

We studied the effects of DL-a-difluoromethylarginine (DFMA) and DL-a-difluoromethylomithine (DFMO), specific, irreversible inhibitors of arginine decarboxylase (ADC) and omithine decarboxylase (ODC), respectively, on organogenesis growth and titers of free polyamines and conjugated putrescines (hydroxycinnamoyl putrescines) in tobacco (Nicotiana tabacum cv Xanthi n.c.)calli. These results suggest that ADC and ODC regulate putrescine biosynthesis during early and later stages of tobacco callus development, respectively. ADC appears active in biosynthesis of large levels of free amines (agmatine and putrescine) while ODC appears active only in biosynthesis of large levels of putrescine conjugates (hydroxycinnamoyl putrescines). DFMA inhibits the fresh and dry weight increases of tobacco calli, whereas DFMO even promoted the fresh and dry weight increases, thus supporting the view that ADC is important for cell division and callus induction. Inhibition of ODC activity by DFMO resulting in an amide deficiency after 4 weeks of culture facilates the expression of differentiated cell functions. Formation of buds is associated with a significant decrease of hydroxycinnamoyl putrescines.Polyamines and their biosynthetic enzymes may play an important role in many aspects of plant development including growth, differentiation, senescence, and response to stress (1, 10, 26). Increased polyamine synthesis appears necessary for cell proliferation to occur (3). Amides formed between hydroxycinnamic acid and amines are widely distributed in the plant kingdom (17, 18). Accumulation of hydroxycinnamic acid amides correlates with leaf emergence and flowering in several plants (5,17,19). Tobacco stem apices, callus tissues, and cell cultures often contain polyamines conjugated with cinnamic acids (4,5,11,20). Some functional roles of these compounds have been suggested. Caffeoyl putrescine and other amides such as caffeoyl spermidine have been found in large concentrations in reproductive organs oftobacco, and it has been proposed that their formation is functionally linked with reproduction (5). In addition, since tobacco plants infected with tobacco mosaic virus react by increasing levels of polyamine conjugates, and virus multiplication is retarded in their presence, a role for these compounds in virus resistance has been suggested (15, 19). Recent results indicate that hydroxycinnamoyl putrescines, when included in the medium, interfere in vitro with hormones in the control of cell multiplication and differentiation of tobacco leaf explants (16).For in vitro cultures, it appears that the intracellular levels of putrescine and hydroxycinnamoyl putrescines are markedly enhanced when the cultures are induced to proliferate (14). The differentiation of buds is always accompanied by significant changes in putrescine and hydroxycinnamoyl putrescine levels (14). Increasing levels were found during the first week in culture when cell multiplication is rapid. Then levels declined sharply after 3 weeks of culture as the rate of ...

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“…Previous reports have shown that in tobacco plants putrescine is synthetized from arginine (by ADC' via agmatine) and ornithine (by ODC) (28,29).…”

Section: Introductionmentioning

confidence: 99%

Effects of the Suicide Inhibitors of Arginine and Ornithine Decarboxylase Activities on Organogenesis, Growth, Free Polyamine and Hydroxycinnamoyl Putrescine Levels in Leaf Explants of Nicotiana Xanthi n.c. Cultivated in Vitro in a Medium Producing Callus Formation

Burtin¹,

Martin-Tanguy²,

Paynot³

et al. 1989

Plant Physiol.

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“…A clear role for ADC has still to be identified, however. In general, it has been suggested that changes in ODC may regulate cell division in actively growing tissues, whereas ADC may regulate cell extension and secondary metabolic processes such as alkaloid biosynthesis (Tiburcio et al, 1990). Putrescine levels are not only dependent on ADC and ODC but also on other metabolic pathways and transport.…”

mentioning

confidence: 99%

Arginine Decarboxylase and Putrescine Oxidase in Ovaries of Pisum sativum L. (Changes during Ovary Senescence and Early Stages of Fruit Development)

Pérez‐Amador

Carbonell²

1995

Plant Physiol.

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Enzymatic activities involved in putrescine metabolism in ovaries of /%um sativum 1. during ovary senescence and fruit set were investigated. Accumulation of putrescine was observed during incubation of extracts from gibberellic acid-treated unpollinated ovaries (young developing fruits) but not in extracts from untreated ovaries (senescent ovaries). Extracts from pea ovaries showed arginine decarboxylase (ADC) activity, but ornithine decarboxylase and arginase activity were not detected. ADC activity decreased in presenescent ovaries and increased markedly after induction of fruit set with gibberellic acid. lncreases in ADC activity were also observed with application of other plant growth substances (benzyladenine and 2,4-dichlorophenoxyacetic acid), after pollination, and in the slender (Ia cry") pea mutant. By contrast, putrescine oxidase activity increased in presenescent ovaries but did not increase during early fruit development. All of these results suggest that ADC and putrescine oxidase are involved in the control of putrescine metabolism. Ovary senescence is characterized by the absence of putrescine biosynthesis enzymes and increased levels of putrescine oxidase and fruit development by an increase in ADC and a constant leve1 of putrescine oxidase.

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“…Samples were ground in chilled mortars in a ratio of 100 mg fresh weight/ml of 100 mm K-phosphate (pH 7.5) containing 10 mM DTT, 20 mm sodium ascorbate, 5 mm EDTA, and 1 mM pyridoxal phosphate. Purified insoluble PVP was added to the extract at 0.5 g wet weight/g tissue to absorb phenolics (19). The extract was sonicated as previously described (19) (19).…”

mentioning

confidence: 99%

Polyamine Metabolism and Osmotic Stress

Tiburcio¹,

Masdéu²,

Dumortier³

et al. 1986

Plant Physiol.

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Cereal leaves subjected to the osmotica routinely used for protoplast isolation show a rapid increase in arginine decarboxylase activity, a massive accumulation of putrescine, and slow conversion of putrescine to the higher polyamines, spermidine, and spermine (HE Flores, AW Galston 1984 Plant Physiol 75: 102). Mesophyll protoplasts from these leaves, which have a high putrescine:polyamine ratio, do not undergo sustained division. By contrast, in Nicotiana, Capsicum, Datura, Trigonelia, and Vigna, dicot genera that readily regenerate plants from mesophyll protoplasts, the response of leaves to osmotic stress is opposite to that in cereals. Putrescine titer as well as arginine and ornithine decarboxylase activities decline in these osmotically stressed dicot leaves, while spermidine and spermine titers increase. Thus, the putrescine:polyamine ratio in Vigna protoplasts, which divide readily, is 4-fold lower than in oat protoplasts, which divide poorly. We suggest that this differing response of polyamine metabolism to osmotic stress may account in part for the failure of cereal mesophyll protoplasts to develop readily in vitro.Regeneration of entire plants from mesophyll protoplasts of Gramineae is still difficult (4), with only one authenticated report in the literature (21). By contrast, in the Solanaceae (3) or Leguminosae (11,13,14), many species of plants have been successfully regenerated from protoplasts.A decade ago, when we observed that PAs2 could retard the rapid senescence and lysis of oat protoplasts (1, 8), we initiated a detailed study of the role of PAs in plant cells (16). We were surprised to find that the Put content of mesophyll protoplasts of oat is 5 to 10 times higher than that of the leaves from which they were derived. Later work showed that cereal leaves subjected to 0.4 to 0.6 M sorbitol exhibit a rapid increase in ADC activity, a massive accumulation of Put, and very slow changes in the higher PAs, Spd, and Spm (5, 6), which are normally formed from Put.In the present investigation, we have studied the effect of osmotic stress in tobacco and other species that can be readily regenerated from protoplasts. The results indicate that tobacco response differs from that observed previously for cereals during osmotic stress (18 by N:P:K: analysis, Hydroponics Chemical Co., Copley, OH) and grown in a controlled chamber under a 16-h light/8-h dark photoperiod (9:1 energy mixture of fluorescent and incandescent light at 17.6 Wm-2) at 240 C.Osmotic Treatment of the Excised Leaves. Median leaves from about 2-month-old tobacco, pepper and Datura or about 1-month-old Trigonella or moth bean or the first leaf of 8-d-old oat seedlings were excised. The lower epidermis was peeled off, and leaf discs (2 cm diameter) or segments (5 cm length) were floated in the dark, unless otherwise indicated, at room temperature over 10 ml 1 mM K-phosphate (pH 5.8) contained in a 100 x 15 mm Petri dish, in the absence (control) or presence of osmotica (0.6 M sorbitol) for various incubation times.Preparation...

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Correlation between Polyamines and Pyrrolidine Alkaloids in Developing Tobacco Callus

Cited by 109 publications

References 13 publications

Effects of the Suicide Inhibitors of Arginine and Ornithine Decarboxylase Activities on Organogenesis, Growth, Free Polyamine and Hydroxycinnamoyl Putrescine Levels in Leaf Explants of Nicotiana Xanthi n.c. Cultivated in Vitro in a Medium Producing Callus Formation

Effects of the Suicide Inhibitors of Arginine and Ornithine Decarboxylase Activities on Organogenesis, Growth, Free Polyamine and Hydroxycinnamoyl Putrescine Levels in Leaf Explants of Nicotiana Xanthi n.c. Cultivated in Vitro in a Medium Producing Callus Formation

Arginine Decarboxylase and Putrescine Oxidase in Ovaries of Pisum sativum L. (Changes during Ovary Senescence and Early Stages of Fruit Development)

Polyamine Metabolism and Osmotic Stress

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