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Casati S, Ottria R, Baldoli E, Lopez E, Maier JAM, Ciuffreda P. Effects of cytokinins, cytokinin ribosides and their analogs on the viability of normal and neoplastic human cells. Anticancer Res 2011; 31:3401-3406. [PMID: 21965753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We examined the effects of some cytokinins and cytokinin ribosides including a series of adenosine analogs differently substituted in the N(6) position, along with some hypoxanthine derivatives on the viability of normal and neoplastic human cells. Cytokinins such as trans-zeatin, isopentenyladenine and benzyladenine do not show any effect, while cytokinin ribosides such as trans-zeatin riboside, isopentenyladenosine, and benzylaminopurine riboside impair the viability of normal and neoplastic cells, apart from colon carcinoma LoVo cells.
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Affiliation(s)
- Silvana Casati
- Dipartimento di Scienze Cliniche "Luigi Sacco", Università degli Studi di Milano, Via G.B. Grassi, 74 - 20157 Milano, Italy
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Takei K, Dekishima Y, Eguchi T, Yamaya T, Sakakibara H. A new method for enzymatic preparation of isopentenyladenine-type and trans-zeatin-type cytokinins with radioisotope-labeling. J Plant Res 2003; 116:259-263. [PMID: 12728344 DOI: 10.1007/s10265-003-0098-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2002] [Accepted: 03/06/2003] [Indexed: 05/24/2023]
Abstract
We describe a new enzymatic reaction method for the preparation of the radioisotope-labeled cytokinins isopentenyladenine (iP), trans-zeatin (tZ), and their ribosides. The method is based on the three enzyme activities of an adenylate isopentenyltransferase (IPT; EC 2.5.1.27) from Arabidopsis thaliana, an alkaline phosphatase (EC 3.1.3.1) from calf intestine, and a purine-nucleoside phosphorylase (EC 2.4.2.1) from Escherichia coli. The A. thaliana IPT, AtIPT7, utilized both dimethylallyldiphosphate and 4-hydroxy-3-methyl-2-( E)-butenyl diphosphate as isoprenoid donors. The dual specificity of the substrates enabled us to produce iP-type and tZ-type cytokinins separately in the same system simply by switching the substrates. Our method affords a much higher yield of the labeled products than the chemical reaction methods previously used. These labeled compounds will be useful tools for cytokinin research, such as receptor-ligand assays and cell metabolism studies.
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Affiliation(s)
- Kentaro Takei
- Plant Science Center, RIKEN (The Institute of Physical and Chemical Research), 1-7-22 Suehiro, Tsurumi, Yokohama 230-0045, Japan
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Lexa M, Genkov T, Malbeck J, Machácková I, Brzobohatý B. Dynamics of endogenous cytokinin pools in tobacco seedlings: a modelling approach. Ann Bot 2003; 91:585-97. [PMID: 12646503 PMCID: PMC4242250 DOI: 10.1093/aob/mcg061] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Recent advances in cytokinin analysis have made it possible to measure the content of 22 cytokinin metabolites in the tissue of developing tobacco seedlings. Individual types of cytokinins in plants are interconverted to their respective forms by several enzymatic activities (5'-AMP-isopentenyltransferase, adenosine nucleosidase, 5'-nucleotidase, adenosine phosphorylase, adenosine kinase, trans-hydroxylase, zeatin reductase, beta-glucosidase, O-glucosyl transferase, N-glucosyl transferase, cytokinin oxidase). This paper reports modelling and measuring of the dynamics of endogenous cytokinins in tobacco plants grown on media supplemented with isopentenyl adenine (IP), zeatin (Z) and dihydrozeatin riboside (DHZR). Differences in phenotypes generated by the three cytokinins are shown and discussed, and the assumption that substrate concentration drives enzyme kinetics underpinned the construction of a simple mathematical model of cytokinin metabolism in developing seedlings. The model was tested on data obtained from liquid chromatography/tandem mass spectrometry cytokinin measurements on tobacco seedlings grown on Murashige and Skoog agar nutrient medium, and on plants grown in the presence of IP, Z and DHZR. A close match was found between measured and simulated data, especially after a series of iterative parameter searches, in which the parameters were set to obtain the best fit with one of the data sets.
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Affiliation(s)
- Matej Lexa
- Masaryk University Brno, Department of Functional Genomics and Proteomics, Kotlárská 2, 611 37 Brno, Czech Republic.
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Abstract
Following uptake of [(3)H]zeatin riboside and [(3)H]dihydrozeatin riboside by girdled lupin (Lupinus angustifolius L.) stems via the transpiration stream, rapid lateral movement of the radioactivity from xylem to bark was observed. Short-term studies with intact stems, and other studies with excised stem tissues, revealed that the ribosides and/or the corresponding nucleotides were the cytokinin forms which actually moved into the bark tissues. Relative to cytokinin metabolism in xylem plus pith, metabolism in bark was both more rapid and more complex. Riboside cleavage and formation of the O-acetylzeatin and O-acetyldihydrozeatin ribosides and nucleotides were almost completely confined to bark tissues. Exogenous (3)H-labelled O-acetylzeatin riboside was converted to zeatin riboside in bark tissue, but the presence of the acetyl group suppressed degradation to adenine metabolites. The sequestration and modification of xylem cytokinins by stem tissues probably contributes significantly to the cytokinin status of the shoot. New cytokinins identified by mass spectrometry in lupin were: O-acetyldihydrozeatin 9-riboside, a metabolite of exogenous dihydrozeatin riboside in stem bark; O-methylzeatin nucleotide and O-methyldihydrozeatin 9-riboside, metabolites of endogenous cytokinins in stem bark; O-methylzeatin nucleotide and O-methylzeatin 9-riboside, metabolites of exogenous zeatin riboside in excised pod walls.
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Affiliation(s)
- Ren Zhang
- Research School of Biological Sciences, The Australian National, University, PO Box 475, ACT 2601, Canberra, Australia
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Zubko E, Adams CJ, Macháèková I, Malbeck J, Scollan C, Meyer P. Activation tagging identifies a gene from Petunia hybrida responsible for the production of active cytokinins in plants. Plant J 2002; 29:797-808. [PMID: 12148537 DOI: 10.1046/j.1365-313x.2002.01256.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Cytokinins (CKs) are phytohormones that play an important role in plant growth and development. Although the first naturally produced CK, zeatin, was isolated almost four decades ago, no endogenous gene has been shown to produce active CKs in planta. In an activation tagging experiment we have identified a petunia line that showed CK-specific effects including enhanced shooting, reduced apical dominance and delayed senescence and flowering. This phenotype correlated with the enhanced expression of a gene we labelled Sho (Shooting). Sho, which encodes a protein with homology to isopentenyl transferases (IPTs), also causes CK-specific effects when expressed in other plant species. In contrast to the ipt gene from Agrobacterium, which primarily increases zeatin levels, Sho expression in petunia and tobacco especially enhances the levels of certain N6-(delta2-isopentenyl) adenosine (2iP) derivatives. Our data suggest that Sho encodes a plant enzyme whose activity is sufficient to produce active CKs in plants.
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Affiliation(s)
- Elena Zubko
- Leeds Institute for Plant Biotechnology and Agriculture, Centre for Plant Sciences, The University of Leeds, UK
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Azmi A, Dewitte W, Van Onckelen H, Chriqui D. In situ localization of endogenous cytokinins during shooty tumor development on Eucalyptus globulus Labill. Planta 2001; 213:29-36. [PMID: 11523653 DOI: 10.1007/s004250000476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Our previous results demonstrated that endogenous cytokinins are involved in the shooty potential of tumors initiated on Eucalyptus globulus plantlets inoculated with Agrobacterium tumefaciens strain 82.139 [A. Azmi et al. (1997a) Plant Sci 127: 81-90]. In order to investigate whether or not these hormones are distributed homogeneously in the tumors prior to the onset of bud regeneration, decapitated hypocotyls were inoculated with the strain C58pMP90/T139 GUS-INT harboring the wild transferred DNA (T-DNA) of strain 82.139 tagged with the beta-glucuronidase (gus)-reporter gene. In situ immunolocalization of zeatin, dihydrozeatin and isopentenyladenine was performed in the developing tumors and combined with the histo-enzymological beta-glucuronidase assay. It was found that the expression of the T-DNA was restricted to only some small areas located deeply in the tumors. These sites were also provided with a high cytokinin signal while the untransformed parts of the tumors displayed a weaker signal, except in the early differentiating tracheary elements. The regenerated buds were untransformed and originated from superficial parts of the tumors provided with a moderate signal for cytokinins. The method of colocalization of both cytokinins and gus expression developed here might be helpful for further studies concerning the role of these hormones in controlling gene expression at cell and tissue levels.
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Affiliation(s)
- A Azmi
- Université Pierre et Marie Curie, Laboratoire CEMV, Paris, France
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Faiss M, Zalubìlová J, Strnad M, Schmülling T. Conditional transgenic expression of the ipt gene indicates a function for cytokinins in paracrine signaling in whole tobacco plants. Plant J 1997; 12:401-15. [PMID: 9301091 DOI: 10.1046/j.1365-313x.1997.12020401.x] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
This study investigated whether an increased production of the plant hormone cytokinin in roots, the main site of its synthesis and putative signaling organ, can influence developmental events, such as growth of axillary shoot meristems or leaf senescence, in the plant shoot. To this end, transgenic tobacco plants (Nicotiana tabacum L.) were generated that conditionally overproduce cytokinins. These plants harbour the ipt gene under the transcriptional control of a modified 35S promoter that is repressed in plants with high titers of tetracycline repressor protein. De-repression of transcription led to a rapid more than 50-fold increase of hormone concentration. The time course of changes in the steady-state levels of 16 different cytokinin metabolites, as a consequence of IPT enzyme activity, was monitored in different plant tissues. Zeatin riboside was the first and most dramatically increased product; zeatin, dihydrozeatin and glucosides accumulated later. The consequences of enhanced cytokinin synthesis remained mainly restricted to the site of hormone production. For example, de-repression of ipt gene transcription in lateral buds caused the growth of single buds only at the site of tetracycline application. In reciprocal grafts of transgenic plants with wild-type plants, no biological cytokinin effects, i.e. growth of lateral shoot meristems or sequential leaf senescence, were observed in the non-transgenic plant part. Also, the increase in steady-state levels of cytokinins remained restricted mainly to the transgenic part, despite a specific increase of the zeatin riboside concentration in the transpiration stream. These results question the role of cytokinins as a long-range root-to-shoot signal in correlative control of apical dominance and sequential leaf senescence of tobacco, and support the assumption that this hormone is relevant to paracrine signaling.
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Affiliation(s)
- M Faiss
- Universität Tübingen, Lehrstuhl für Allgemeine Genetik, Germany
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Kobayashi H, Morisaki N, Tago Y, Hashimoto Y, Iwasaki S, Kawachi E, Nagata R, Shudo K. Structural identification of a major cytokinin in coconut milk as 14-O-(3-O-[beta-D-galactopyranosyl-(1-->2)-alpha-D-galactopyranosyl- (1-->3)-alpha-L-arabinofuranosyl]-4-O-(alpha-L-arabinofuranosyl)- beta-d-galactopyranosyl)-trans-zeatin riboside. Chem Pharm Bull (Tokyo) 1997; 45:260-4. [PMID: 9118441 DOI: 10.1248/cpb.45.260] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A cytokinin isolated from the fluid endosperm of Cocos mucifera L. (coconut milk), accounting for more than 20% of the total cytokinin activity, was structurally analyzed by NMR techniques, mass spectrometry, and sugar analysis by high performance liquid chromatography (HPLC). The planar structure of the cytokinin was deduced from its NMR and mass spectrometric data. The structure of the sugar moiety, including its absolute structure, was determined by HPLC analysis of alditol acetates and aldononitrile acetates derived from the cytokinin. The configuration of the sugar-sugar bonds was determined by NMR, and the structure was finally identified as 14-O-(3-O-[-beta-D-galactopyranosyl-(1-->2)-alpha-galactopyranosyl-(1--> 3)- alpha-L-arabinofuranosyl]-4-O-(alpha-L-arabino-furanosyl)-beta-D- galactopyranosyl)-trans-zeatin riboside.
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Affiliation(s)
- H Kobayashi
- Institute of Molecular and Cellular Biosciences, University of Tokyo, Japan
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Upadhyaya NM, Letham DS, Parker CW, Hocart CH, Dart PJ. Do rhizobia produce cytokinins? Biochem Int 1991; 24:123-30. [PMID: 1768251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Two Rhizobium strains were cultured on a defined medium; one was a normal strain of the cowpea group (ANU240) while the other (IC3342) was an unusual but related strain of the same group which induced abnormal shoot development, including proliferation of lateral buds, in nodulated plants. Culture supernatants were examined for the presence of cytokinins by mass spectrometry using deuterium-labelled internal standards and by radioimmunoassay. In culture supernatants of both strains a range of cytokinins was detected and quantified, but N6-(2-isopentenyl)adenine (iP) and zeatin (Z) were the dominant cytokinins. The levels of Z and iP in supernatants of strain IC3342 were 26 and 8 times, respectively, those in supernatants of the strain ANU240. These results appear to provide the first unambiguous identifications of cytokinins in Rhizobium culture media. The cytokinin level in xylem sap of pigeonpea plants inoculated with strain IC3342 was markedly greater than that in plants inoculated with a normal nodulating strain. The abnormal proliferation of lateral buds in the former plants is probably linked to the elevation of cytokinin level in xylem sap caused by strain IC3342.
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Affiliation(s)
- N M Upadhyaya
- Research School of Biological Sciences, Australian National University, Canberra City
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Affiliation(s)
- A E Stafford
- Plant Development Quality Research Unit, U.S. Department of Agriculture, Albany, CA 94710
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McCloskey JA, Hashizume T, Basile B, Ohno Y, Sonoki S. Occurrence and levels of cis-and trans-zeatin ribosides in the culture medium of a virulent strain of Agrobacterium tumefaciens. FEBS Lett 1980; 111:181-3. [PMID: 7358157 DOI: 10.1016/0014-5793(80)80788-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Hashizume T, Sugiyama T, Imura M, Cory HT, Scott MF, McCloskey JA. Determination of cytokinins by mass spectrometry based on stable isotope dilution. Anal Biochem 1979; 92:111-22. [PMID: 371461 DOI: 10.1016/0003-2697(79)90631-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Edström A. Rapid axonal transport in vitro. Effects of derivatives of cyclic AMP and other agents acting on the cyclic AMP system. J Neurobiol 1977; 8:371-80. [PMID: 70512 DOI: 10.1002/neu.480080408] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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MacLeod JK, Summons RE, Letham DS. Mass spectrometry of cytokinin metabolites. Per (trimethylsilyl) and permethyl derivatives of glucosides of zeatin and 6-benzylaminopurine. J Org Chem 1976; 41:3959-67. [PMID: 993897 DOI: 10.1021/jo00887a006] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Jonard R, Bayonove J. [Radiorestoration by 3 cytokinins contained in yeast RNAs and extracts, of scorzonera tumor tissues exposed to cobalt-60 gamma rays]. C R Acad Hebd Seances Acad Sci D 1976; 283:275-7. [PMID: 825274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The 3 natural cytokinins contained both in the extracts and RNA of yeast and the tumor tissues cultivated in vitro, elicit radiorestorative properties from the crown-gall tissues of Scorsonera submitted to Co60 gamma-rays. However the cytokinins produce no stimulating effect whatsoever on the non irradiated tissues that are nontheless highly stimulated by yeast extract and their RNA.
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