Abstract
The incorporation of labelled adenine into cytokinin-like compounds was investigated in intact tomato plants, decapitated tomato roots and cell-free root extracts. In all three cases evidence was found for the incorporation of adenine into endogenous cytokinins. In intact plants and decapitated root systems no evidence was found for the incorporation into cytokinin nucleotides. Cytokinin bases and nucleosides were however, labelled. In the cell-free root extract there was some evidence for the incorporation of labelled adenine into cytokinin nucleotides. This suggests that the biosynthetic process may be strictly compartmentalized. The present results provide no evidence for the relative importance of cytokinin nucleotides in the biosynthetic process. What is clear is that the rate of adenine incorporation into cytokinins is extremely low and that only a small proportion of the cytokinins which became labelled were exported to the shoot via the root exudate.
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References
Chen CM, Ertl JR, Leisner SM and Chang C (1985) Localization of cytokinin biosynthetic sites in pea plants and carrot roots. Plant Physiol 78:510–513
Chen CM and Melitz DK (1979) Cytokinin biosynthesis in a cell-free system from cytokinin-autotrophic tobacco tissue cultures. FEBS Lett 107:15–20
Dyson WH, Fox JE and McChesney JD (1972) Short-term metabolism of urea and purine cytokinins. Plant Physiol 49:506–513
Engelbrecht L (1972) Cytokinins in leaf cuttings of Phaseolus vulgaris L. during their development. Biochem Physiol Pflanzen 163:335–343
Hoagland DR and Snyder WC (1933) Nutrition of strawberry plants under controlled conditions. Proc Am Soc Hort Sci 30:288–294
Lee YH, Mok MC, Mok DWS, Griffin DA and Shaw G (1985) Cytokinin metabolism in Phaseolus embryos. Plant Physiol 77:635–641
Miller CO (1965) Evidence for the natural occurence of zeatin and derivatives: Compounds from maize which promote cell division. Proc Natl Acad Sci USA 54:1052–1054
Nishinari N and Syono K (1980) Cell-free biosynthesis of cytokinins in cultured tobacco cells. Z Pflanzenphysiol 99:383–392
Palni LMS, Horgan R, Darrall NM, Stuchbury T and Wareing PF (1983) Cytokinin biosynthesis in crown-gall tissue of Vinca rosea: The significance of nucleotides. Planta 159:50–59
Short KC and Torrey JG (1972) Cytokinins in seedling roots of pea. Plant Physiol 49:155–160
Stuchbury T, Palni LMS, Horgan R and Wareing PF (1979) the biosynthesis of cytokinins in crown-gall tissues of Vinca rosea. Planta 147:97–102
Van Staden J (1976) Seasonal changes in the cytokinin content of Ginkgo biloda leaves. Physiol Plant 38:1–5
Van Staden J and Forsyth C (1984) Adenine incorporation into cytokinins in aseptically cultured tomato roots. J Plant Physiol 117:249–255
Van Staden J and Forsyth C (1985) Metabolism of kinetin by soybean callus. Plant Growth Regul 3:167–178
Van Staden J and Forsyth C (1986) Maize roots, adenine and cytokinin biosynthesis:-Lack of a positive correlation. S Afr J Bot 52:85–90
Van Staden J and Smith AR (1978) the synthesis of cytokinins in excised roots of maize and tomato under aseptic conditions. Ann Bot 42:751–753
Weiss C and Vaadia Y (1965) Kinetin-like activity in root apices of sunflower plants. Life Sci 4:1323–1326
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The financial support of the CSIR/Israel Collaborative Programme is gratefully acknowledged.
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Dickinson, J.R., Forsyth, C. & Van Staden, J. The role of adenine in the synthesis of cytokinins in tomato plants and in cell-free root extracts. Plant Growth Regul 4, 325–334 (1986). https://doi.org/10.1007/BF00024932
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DOI: https://doi.org/10.1007/BF00024932