Abstract
The interaction of photo- and gravitropic stimulation was studied by analysing the curvature of maize (Zea mays L.) coleoptiles subjected to rotation on horizontal clinostats. Gravitropic curvature in different directions with respect to the stimulation plane was found to be transient. This instability was caused by an increasing deviation of response direction from the stimulation plane towards the caryopsis. The bending angle as such, however, increased steadily. This reorientation of the gravitropic response towards the caryopsis is thought to be caused by the clinostat-elicited nastic curvature found in maize coleoptiles. In contrast, the response to phototropic stimulation was stable, in both, orientation and curving. Although stimulation by gravity was not capable of inducing a stable tropistic response, it could inhibit the response to opposing phototropic stimulation, if the counterstimulation was given more than 90 min after the onset of gravistimulation. For shorter time intervals the influence of the phototropic stimulus obscured the response to the first, gravitropic stimulation. For time intervals exceeding 90 min, however, the phototropic effects disappeared and the response was identical to that for gravity stimulation alone. This gravity-induced inhibition of the phototropic response was confined to the plane of gravity stimulation, because a phototropic stimulation in the perpendicular direction remained unaffected, irrespective of the time interval between the stimulations. This concerned not only the stable phototropic curving, but also the capacity of the phototropic induction to elicit a stable directional memory as described earlier (P. Nick and F. Schäfer, 1988b, Planta 175, 380–388). This was tested by a second bluelight pulse opposing the first. It is suggested that gravity, too, can induce a directional memory differing from the blue-light elicited memory. The mechanisms mediating gravi- and phototropic directional memories are thought to branch off the respective tropistic signal chains at a stage where photo- and gravitropic transduction are still separate.
Similar content being viewed by others
References
Buder, J. (1920) Neue phototropische Fundamentalversuche. Ber. Dtsch. Bot. Ges. 38, 10–19
Hild, V., Hertel, R. (1972) Initial phases of gravity-induced lateral auxin transport and geotropic curvature in corn coleoptiles. Planta 108, 245–258
Nick, P., Schäfer, E. (1988a) Interaction of gravi- and phototropic stimulation in the response of maize (Zea mays L.) coleoptiles. Planta 173, 213–220
Nick, P., Schäfer, E. (1988b) Spatial memory during the tropism of maize (Zea mays L.) coleoptiles. Planta 175, 380–388
Nick, P., Schäfer, E. (1989) Nastic response of maize (Zea mays L.) coleoptiles during clinostat rotation. Planta 179, 123–131
Pekelharing, C.J. (1909) Onderzoekingen over de perceptie van den zwaartekrachtprikkel door planten. J. van Boekhoven, Utrecht
Rawitscher, S. (1932) Der Geotropismus der Pflanzen Fischer, Jena
Sailer, H., Nick, P., Schäfer, E.. (1990) Inversion of gravitropism by symmetric blue light on the clinostat. Planta 180, 378–382
Ullrich, C.H. (1976) Kontinuierlich registrierende Messung der Krümmungsbewegung von Maiskoleoptilen: Schnelle Effekte von Auxinapplikation, Schwerkraft und Blaulicht, pp 78–81. Doctoral Thesis, University of Freiburg, FRG
Author information
Authors and Affiliations
Additional information
This work was supported by the Deutsche Forschungsgemeinschaft and a grant of the Studienstiftung des Deutschen Volkes to P. Nick.
Rights and permissions
About this article
Cite this article
Nick, P., Sailer, H. & Schäfer, E. On the relation between photo- and gravitropically induced spatial memory in maize coleoptiles. Planta 181, 385–392 (1990). https://doi.org/10.1007/BF00195892
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00195892