Summary
The phytochrome system is responsible for the photosensitivity of dormant, isolated apple embryos in culture. Maximum photosensitivity occurs on the second day of culture and it is unaffected by gibberellins (GAs) in concentrations below 10-4M. Higher concentrations of GA decrease the photosensitivity.
The endogenous quantities of GA4 and GA7 were determined in embryos grown at white light, in darkness and in darkness following an exposure to red light. The GA7 level remained unaffected by the light conditions, whereas the amount of GA4 was three times higher in light or red-light-treated cultures than in the dark grown ones.
Similar experiments were done using AMO-1618, an inhibitor of GA biosynthesis, which is also a strong inhibitor of apple seed germination. In this case the level of both GA4 and GA7 was light-independent. These experiments suggest that the phytochrome system participates in the regulation of GAs biosynthesis by mediating one of the last steps of GA4 formation.
Similar content being viewed by others
References
Beevers, L., Loveys, B., Pearson, J. A., Wareing, P. F.: Phytochrome and hormonal control of expansion and greening of etiolated wheat leaves. Planta (Berl.) 90, 286–294 (1970).
Bewley, J. D., Black, M., Negbi, M.: Immediate action of phytochrome in light-stimulated lettuce seeds. Nature (Lond.) 215, 648–649 (1967).
Brian, P. W.: The role of gibberellin-like hormones in regulation of plant growth and flowering. Nature (Lond.) 181, 1122–1123 (1958).
Cross, B. E., Myers, P. L.: The effect of plant growth retardants on the biosynthesis of diterpenes by Gibberella fujikuroi. Phytochem. 8, 79–83 (1969).
Dennis, D. T., Upper, C. D., West, C. A.: An enzymic site of inhibition of gibberellin biosynthesis by AMO-1618 and other plant growth retardants. Plant Physiol. 40, 948–952 (1965).
Dennis, F. G., Nitsch, J. P.: Identification of gibberellins A4 and A7 in immature apple seeds. Nature (Lond.) 211, 781–782 (1966).
Geissman, T. A., Verbiscar, A. J., Phinney, B. O., Cragg, G.: Studies on the biosynthesis of gibberellins from (-) kaurenoic acid in cultures of Gibberella fujikuroi. Phytochem. 5, 933–947 (1966).
Graebe, J. E.: Biosynthesis of kaurene, squalene and phytoene from mevalonate-214C in a cell-free system from pea fruits. Phytochem. 7, 2003–2020 (1968).
Kahn, A.: Promotion of lettuce seed germination by gibberellin. Plant Physiol. 25 333–339 (1960).
Köhler, D.: Die Abhängigkeit der Gibberellinproduktion von Normalerbsen vom Phytochromsystem. Planta (Berl.) 69, 27–33 (1966).
—: Veränderungen des Gibberellingehaltes von Salatsamen nach Belichtung. Planta (Berl.) 70, 42–45 (1966).
Lewak, St., Białek, K., Sińska, I.: The sensitivity of apple seeds germination to light and some growth regulators. Biol. Plantarum (Praha), 12, 291–296 (1970).
—, Smoleńska, G.: Le système phytochrome dans la germination des semences de Pommier. Physiol. vég. 6, 403–408 (1968).
Reid, D. M., Clements, J. B., Carr, D. J.: Red light induction of gibberellin synthesis in leaves. Nature (Lond) 217, 580–582 (1968).
Rollin, P.: Influence de l'acide gibbérellique sur la germination des semences photosensibles. Bull. Soc. franç. Physiol. Véget. 5, 24–26 (1959).
—, Maignan, G.: La nécessité du phytochrome Prl(=P730) pour la germination des akènes de Lactuca sativa L. varieté Reine de Mai. C. R. Acad. Sci. (Paris) 263, 756–759 (1966).
Spector, C., Phinney, B. O.: Gibberellin biosynthesis: Genetic studies in Gibberella fujikuroi. Physiol. Plantarum (Cph.) 21, 127–136 (1968).
Sińska, I., Lewak, St.: Apple seeds gibberellins. Physiol. vég. 8, 661–667 (1970).
Thompson, P. A.: The effect of some promotors and inhibitors on the light controlled germination of strawberry seeds, Fragaria vesca semperflorens Ehr. Physiol. Plantarum (Cph.) 21, 833–841 (1968).
Timson, J.: New method of recording germination data. Nature (Lond.) 207, 216–217 (1965).
Veinberg, E. S., Voeller, B. R.: Induction of fern spore germination. Proc. nat. Acad. Sci. (Wash.) 64, 835–842 (1969).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Smoleńska, G., Lewak, S. Gibberellins and the photosensitivity of isolated embryos from non-stratified apple seeds. Planta 99, 144–153 (1971). https://doi.org/10.1007/BF00388246
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00388246