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. 1982 Jul;70(1):173–178. doi: 10.1104/pp.70.1.173

Cytokinin Structure-Activity Relationships and the Metabolism of N6-(Δ2-Isopentenyl)Adenosine-8-14C in Phaseolus Callus Tissues 1

Machteld C Mok 1,2,3, David W S Mok 1,2,3, Susan C Dixon 1,2,3, Donald J Armstrong 1,2,3, Gordon Shaw 1,2,3
PMCID: PMC1067107  PMID: 16662440

Abstract

The activities of the free base and ribonucleoside forms of cytokinins bearing saturated and unsaturated N6-isoprenoid side chains have been examined in callus cultures derived from Phaseolus vulgaris cv. Great Northern, P. lunatus cv. Kingston, and the interspecific hybrid Great Northern × Kingston. In callus of cv. Great Northern, cytokinins bearing saturated side chains (N6-isopentyladenine, N6-isopentyladenosine, dihydrozeatin, and ribosyldihydrozeatin) were always more active than the corresponding unsaturated analogs (N6-[Δ2-isopentenyl]adenine, N6-[Δ2-isopentenyl]adenosine, zeatin, and ribosylzeatin). In callus of cv. Kinston, the cytokinins bearing unsaturated side chains were either more active or equally as active as the saturated compounds. These differences in cytokinin structure-activity relationships were correlated with differences in the metabolism of 14C-N6-(Δ2-isopentenyl)adenosine. In Great Northern tissues, this cytokinin was rapidly degraded to adenosine; in Kingston tissues, the major metabolite was the corresponding nucleotide. The growth responses of callus of the interspecific hybrid were intermediate between the parental tissues, and the metabolism of 14C-N6-(Δ2-isopentenyl)adenosine by the hybrid callus exhibited characteristics of both parental tissues. The results are consistent with the hypothesis that the weak activity of cytokinins with unsaturated side chains in promoting the growth of Great Northern callus is due to the rapid conversion of these cytokinins to inactive metabolites.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Armstrong D. J., Skoog F. Chromatography of Cytokinins on a Neutral Polystyrene Resin: A Simple Procedure for the Separation of the cis and trans Isomers of Zeatin or Ribosylzeatin. Plant Physiol. 1975 Feb;55(2):237–239. doi: 10.1104/pp.55.2.237. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Fleysher M. H., Hakala M. T., Bloch A., Hall R. H. Synthesis and biological activity of some N6-alkyladenosines. J Med Chem. 1968 Jul;11(4):717–720. doi: 10.1021/jm00310a018. [DOI] [PubMed] [Google Scholar]
  3. Krasnuk M., Witham F. H., Tegley J. R. Cytokinins extracted from pinto bean fruit. Plant Physiol. 1971 Sep;48(3):320–324. doi: 10.1104/pp.48.3.320. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Laloue M., Terrine C., Gawer M. Cytokinins: formation of the nucleoside-5'-triphosphate in tobacco and Acer cells. FEBS Lett. 1974 Sep 15;46(1):45–50. doi: 10.1016/0014-5793(74)80331-5. [DOI] [PubMed] [Google Scholar]
  5. Mok M. C., Kim S. G., Armstrong D. J., Mok D. W. Induction of cytokinin autonomy by N,N'-diphenylurea in tissue cultures of Phaseolus lunatus L. Proc Natl Acad Sci U S A. 1979 Aug;76(8):3880–3884. doi: 10.1073/pnas.76.8.3880. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Mok M. C., Mok D. W., Armstrong D. J. Differential cytokinin structure-activity relationships in phaseolus. Plant Physiol. 1978 Jan;61(1):72–75. doi: 10.1104/pp.61.1.72. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Mok M. C., Mok D. W., Armstrong D. J., Rabakoarihanta A., Kim S. G. Cytokinin autonomy in tissue cultures of phaseolus: a genotype-specific and heritable trait. Genetics. 1980 Mar;94(3):675–686. doi: 10.1093/genetics/94.3.675. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Paces V., Werstiuk E., Hall R. H. Conversion of N-(Delta-Isopentenyl)adenosine to Adenosine by Enzyme Activity in Tobacco Tissue. Plant Physiol. 1971 Dec;48(6):775–778. doi: 10.1104/pp.48.6.775. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Poling A., Thompson T. The effects of d-amphetamine on the automaintained key pecking of pigeons. Psychopharmacology (Berl) 1977 Mar 16;51(3):285–288. doi: 10.1007/BF00431637. [DOI] [PubMed] [Google Scholar]
  10. Schmitz R. Y., Skoog F. The use of dimethylsulfoxide as a solvent in the tobacco bioassay for cytokinins. Plant Physiol. 1970 Apr;45(4):537–538. doi: 10.1104/pp.45.4.537. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Sondheimer E., Tzou D. S. The Metabolism of Hormones during Seed Germination and Dormancy: II. The Metabolism of 8-C-Zeatin in Bean Axes. Plant Physiol. 1971 Apr;47(4):516–520. doi: 10.1104/pp.47.4.516. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Whitty C. D., Hall R. H. A cytokinin oxidase in Zea mays. Can J Biochem. 1974 Sep;52(9):789–799. doi: 10.1139/o74-112. [DOI] [PubMed] [Google Scholar]

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