Phytohormone-induced GABA production in transformed root cultures ofDatura stramonium: anin vivo15N NMR study

Ford, Y.-Yannick; Ratcllffe, R.G.; Robins, Richard J.

doi:10.1093/jxb/47.6.811

Cited by 37 publications

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“…For example the addition of polyamine-biosynthesis inhibitors to thin cell layers of tobacco caused cell expansion and an inhibition of cell division and rhizogenesis; and these eects could Trace A, 11-d-old roots, control experiment; trace B, 12-d-old roots, with DFMO added to a ®nal concentration of 2 mM on day 3; trace C, 11-d-old roots, with DFMA added to a ®nal concentration of 2 mM on day 3. Peak assignments (Ford et al 1996a): 1, conjugated polyamine amide-N; 2, glutamine amide-N; 3, hyoscyamine; 5, glutamate a-amino-N; 6, contributions from conjugated polyamine amino-N, GABA amino-N, and possibly ornithine and lysine side-chain N-atoms. The peak labelled with an asterisk (*) is the signal from the [ 15 N]urea chemical shift standard at A298.8 ppm.…”

Section: Resultsmentioning

confidence: 99%

“…For example, treating transformed roots of D. stramonium with a-naphthaleneacetic acid (NAA) and kinetin (N 6 -furfurylaminopurine) leads to changes in primary nitrogen metabolism (Ford et al 1996a) as well as to inhibition of hyoscyamine accumulation (Robins et al 1991c;Ford et al 1996b). The reduction in hyoscyamine accumulation appears to occur because of an eect of the phytohormones on putrescine methylation (Fig.…”

Section: Introductionmentioning

confidence: 99%

“…Metabolic relationships between polyamines and alkaloids in transformed D. stramonium roots. ACC, 1-aminocyclopropane-1-carboxylic acid; CHA, cyclohexylamine; DecSAM, decarboxy-Sadenosylmethionine; MGBG, methylglyoxal-bis(guanyl)hydrazone; MPO, N-methylputrescine oxidase; SAM, S-adenosylmethionine; SAMDC, S-adenosylmethionine decarboxylase; SPDsyn, spermidine synthase; SPMsyn, spermine synthase; TRI, tropinone reductase I; TRII, tropinone reductase II monitoring complex metabolic events in plants (Ratclie 1994), and recently we have shown that in-vivo 15 N-NMR can be used in studies of nitrogenous secondaryproduct metabolism (Ford 1995;Ford et al 1994Ford et al , 1996a. The advantage of NMR in this context is that several metabolic pools can be monitored simultaneously, allowing time-dependent correlations to be established between metabolites during the response of a tissue to a physiological perturbation.…”

Section: Introductionmentioning

confidence: 99%

“…The advantage of NMR in this context is that several metabolic pools can be monitored simultaneously, allowing time-dependent correlations to be established between metabolites during the response of a tissue to a physiological perturbation. We have used in-vivo 15 N-NMR to observe changes in primary and secondary nitrogen metabolism in transformed root cultures following their exposure to exogenous growth regulators, and in an earlier paper we showed that phytohormonetreatment leads to a redirection of primary nitrogen metabolism and the synthesis of c-aminobutyric acid (GABA) in de-dierentiating transformed root cultures of D. stramonium (Ford et al 1996a). Here we report NMR measurements during the initial stages of phytohormone-induced de-dierentiation that indicate that free polyamines may be important in this process, and we then describe experiments that show that inhibitors of putrescine biosynthesis protect the roots against dedierentiation.…”

Section: Introductionmentioning

confidence: 99%

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In vivo nuclear-magnetic-resonance analysis of polyamine and alkaloid metabolism in transformed root cultures of Datura stramonium L.: evidence for the involvement of putrescine in phytohormone-induced de-differentiation

Ford

Ratcliffe

Robins

1998

Planta

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The utilisation and accumulation of 15 Nlabeled metabolites by a 15 N-labeled transformed root culture of Datura stramonium L. was investigated by in vivo 15 N-nuclear-magnetic-resonance (NMR) spectroscopy. After resuspension in spent growth medium, the pools of [ 15 N]glutamate and [ 15 N]glutamine were rapidly depleted and there was an increase in the 15 N-NMR signals from conjugated putrescines and hyoscyamine. The signal from the conjugated putrescines passed through a maximum 2 d after the roots were resuspended, and it was concluded that putrescine could be stored as putrescine conjugates prior to its utilisation in other pathways. The transient accumulation of 15 Nlabel in the hydroxy-cinnamoylputrescines was reduced when the de-dierentiation of the root cultures into a suspension culture was initiated by exposure to a medium containing a-napthaleneacetic acid and kinetin. This led to the hypothesis that phytohormone-induced de-dierentiation of the root cultures required the presence of free polyamines, and this was tested using two potent inhibitors of putrescine biosynthesis, DL-a-di¯uor-omethylarginine and DL-a-di¯uoromethylornithine. Invivo 15 N-NMR spectra of roots grown in 15 N-enriched medium supplemented with these inhibitors showed that the 15 N-labelling of the conjugated polyamines and hyoscyamine was markedly reduced. DL-a-di¯uoro-methylarginine also prevented the phytohormone induced de-dierentiation of the root cultures, and this eect could be reversed by the supply of exogenous putrescine. Thus the supply of putrescine appears to play a crucial role in mediating the phytohormone induced de-dierentiation of the root culture.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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In vivo nuclear-magnetic-resonance analysis of polyamine and alkaloid metabolism in transformed root cultures of Datura stramonium L.: evidence for the involvement of putrescine in phytohormone-induced de-differentiation

Ford

Ratcliffe

Robins

1998

Planta

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“…In carrot suspension cells the activity of glutamate decarboxylase increases with a decrease in the cytoplasmic pH: it has been suggested that this reaction plays a role in pH homeostasis (5). Glutamate decarboxylase is also activated by calcium-calmodulin (51), and is potentially part of a stress response (8).…”

Section: Resultsmentioning

confidence: 99%

Noninvasive NMR studies of metabolism in cultured Catharanthus roseus cells

Vogel

Lundberg

Bagh

1999

In Vitro Cell.Dev.Biol.-Plant

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Nuclear magnetic resonance (NMR) spectroscopy provides a unique modality for the study of tissue-cultured plant cells. One of its major attractions is that it allows noninvasive studies of plant material. In addition, it can provide insight into the pH in the vacuole and cytoplasm, and into the compartmentalization of certain metabolites. In this review we show how phosphorus-31 NMR is used to study intracellular pH, phosphate uptake and storage, and energy metabolism in suspension ceils of Catharanthus roseus. In addition, multinuclear NMR studies of the uptake of ammonium and the gradients of K + over the membrane are discussed as well. The use of two-dimensional NMR for the study of whole cell extracts is also described. Finally, we show how nitrogen-14 and nitrogen-15 NMR are used to obtain information about the assimilation of inorganic sources in developing carrot somatic embryos. These NMR studies provide a unique insight into the metabolism of tissue-cultured plant cells.

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Nuclear Magnetic Resonance in the Analysis of Foodstuffs and Plant Materials

Ropp

McCarthy

2000

Encyclopedia of Analytical Chemistry

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Nuclear magnetic resonance (NMR) is an experimental technique based on the interaction between an applied magnetic field and nuclear magnetic moments in a sample. NMR provides information on material composition, molecular structure, physical structure, physical properties and dynamics of phase changes. NMR is a noncontacting and noninvasive measurement. NMR has been used for the routine analysis of foodstuffs and plant materials. NMR is used in the analysis of foods to detect moisture content, solid/liquid ratio in fats, adulteration of juices and characterization of texture. Applications of NMR to plant materials include observation and characterization of metabolites and ions, determination of pH and following changes of these over time. NMR is also used to determine structures of natural products isolated from plants. Magnetic resonance imaging (MRI) is used in both foodstuffs and plant materials to study morphology and also water transport, diffusion and variations of these under different conditions. The response of NMR is linear from the detection limits of approximately 10 ppb to 100%. The accuracy of the technique depends upon the signal‐to‐noise ratio (S/N), which is a function of the sample size, applied magnetic field strength, the radiofrequency (RF) coil, the spectrometer hardware and experimental parameters. Typical accuracy is 0.5% for composition and 1–5% for viscosity.

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Phytohormone-induced GABA production in transformed root cultures ofDatura stramonium: anin vivo¹⁵N NMR study

Cited by 37 publications

References 0 publications

In vivo nuclear-magnetic-resonance analysis of polyamine and alkaloid metabolism in transformed root cultures of Datura stramonium L.: evidence for the involvement of putrescine in phytohormone-induced de-differentiation

In vivo nuclear-magnetic-resonance analysis of polyamine and alkaloid metabolism in transformed root cultures of Datura stramonium L.: evidence for the involvement of putrescine in phytohormone-induced de-differentiation

Noninvasive NMR studies of metabolism in cultured Catharanthus roseus cells

Nuclear Magnetic Resonance in the Analysis of Foodstuffs and Plant Materials

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