Abstract
Isolated Avena coleoptiles were decapitated at different distances from the tip and then placed horizontally, after which the geotropic curvature was measured. No geotropic curvature could be detected during the first 3 h. Later, upward curvature occurred which was found to depend inversely on the length of the decapitated tips. When the tips of maize roots or Avena coleoptiles were placed on the cut surface of decapitated Avena coleoptiles, the coleoptiles showed a significantly stronger upward curvature as compared to controls which had been provided with agar blocks on the cut surface. The same upward curvature was found with decapitated coleoptiles provided with agar blocks containing 10-6 or 10-7 M indoleacetic acid (IAA). After application of abscisic acid (ABA) at concentrations of 10-6 and 10-8 M to the decapitated coleoptiles, the curvature observed was not different from that of the controls; at higher concentrations of ABA the curvature was found to be lower than that of the controls. It is concluded that root tips secrete a substance which may replace the effect of IAA in coleoptiles. The results are discussed in view of the validity of the Cholodny-Went hypothesis for the geotropic reaction of roots.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Abbreviations
- ABA:
-
abscisic acid
- IAA:
-
3-indoleacetic acid
References
Boysen Jensen, P. (1933) Über den Nachweis von Wuchsstoff in Wurzeln. Planta 19, 345–350
Cholodny, N. (1928) Beitrage zur hormonalen Theorie von Tropismen. Planta 6, 118–134
Davies, P.J., Doro, J.A., Tarbox, A.W. (1976) The movement and physiological effect of indoleacetic acid and following point applications to root tips of Zea mays. Physiol. Plant. 36, 333–337
Konings, H. (1967) On the mechanism of the transverse distribution of auxin in geotropically exposed pea roots. Acta Bot. Neerl. 16, 161–176
Menschick, R., Hild, V., Hager, A. (1977) Decarboxylierung von Indolylessigsäure im Zusammenhang mit dem Phototropismus in Avena-Koleoptilen. Planta 133, 223–228
Ohwaki, Y., Tsurumi, S. (1976) Auxin transport and growth in intact roots of Vicia faba. Plant Cell Physiol. 17, 1329–1342
Pilet, P.E. (1973) Growth inhibitor from the root cap of Zea mays. Planta 111, 275–278
Pilet, P.E. (1974) Abscisic acid as a root growth inhibitor: physiological analyses. Planta 122, 299–302
Rehm, M.M., Cline, M.G. (1973) Rapid growth inhibition of Avena coleoptile segments by abscisic acid. Plant Physiol. 51, 93–96
Schurzmann, M., Hild, V. (1980) Effect of indoleacetic acid, abscisic acid, root tips and coleoptile tips on growth and curvature of maize roots. 150, 32–36
Shaw, S., Wilkins, M.B. (1973) The source and lateral transport of growth inhibitors in geotropically stimulated roots of Zea mays and Pisum sativum. Planta 109, 11–26
Söding, H. (1925) Zur Kenntnis der Wuchshormone in der Haferkoleoptile. Jahrb. Wiss. Bot. 64, 587–603
Went, F.W., Thimann, K.V. (1937) Phytohormones. Macmillan, New York
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Steen, M., Hild, V. Geotropic curvature of decapitated Avena coleoptiles after application of tips of maize roots, tips of Avena coleoptiles, indoleacetic acid, or abscisic acid. Planta 150, 37–40 (1980). https://doi.org/10.1007/BF00385612
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00385612