Abstract
Phototropic stimulation induces a spatial memory. This was inferred from experiments with maize (Zea mays L.) coleoptiles involving opposing blue-light pulses, separated by variable time intervals, and rotation on a horizontal clinostat (Nick and Schäfer, 1988b, Planta 175, 380–388). In those experiments, individual seedlings either curved towards the first or towards the second pulse, or they remained straight. Bending, if it occurred, seemed to be an all-or-none response. Intermediates, i.e. plants, bending only weakly, were not observed. In the first part of the present study it was attempted to create such intermediates. For this purpose the strength of the first, inducing, and the second, opposing, pulse was varied. The result was complex: (i) Individual seedlings maintained the all-or-none expression of spatial memory. (ii) However, on the level of the whole population, the time intervals at which a given response type dominated depended on the fluence ratio. (iii) Furthermore, the final curvature was determined by the fluence ratio. These results are discussed in terms of a blue-light-induced transverse polarity. This polarity initiates from a labile precursor, which can be reoriented by an opposing stimulation (indicated by the strong bending towards the second pulse). The strong curvatures towards the first pulse over long time intervals reveal that, eventually, the blue-light-induced transverse polarity becomes stabilised and thus immune to the counterpulse. In the second part of the study, the relation between phototropic transduction and transverse polarity was characterised by a phenomenological approach involving the following points: (i) Sensory adaptation for induction of transverse polarity disappears with a time course similar to that for phototropic sensory adaptataion. (ii) The fluence-response for induction of transverse polarity is a saturation curve and not bell-shaped like the curve for phototropism. (iii) For strong counterpulses and long time intervals the clinostat-elicited nastic response (Nick and Schäfer 1989, Planta 179, 123–131) becomes manifest and causes an “aiming error” towards the caryopsis. (iv) Temperature-sensitivity of polarity induction was high in the first 20 min after induction, then dropped sharply and rose again with the approach of polarity fixation. (v) Stimulus-summation experiments indicated that, for different inducing fluences, the actual fixation of polarity happened at about 2 h after induction. These experiments point towards an early separation of the transduction chains mediating phototropism and transverse polarity, possibly before phototropic asymmetry is formed.
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References
Arisz, W.H. (1915) Untersuchungen über den Phototropismus. Rec. Trav. Bot. Neerl. 12, 44–216
Briggs, W.R. (1960) Light dosage and phototropic response of corn and oat coleoptiles. Plant Physiol. 35, 951–962
Buder, J. (1920) Neue phototropische Fundamentalversuche. Ber. Dtsch. Bot. Ges. 28, 10–19
Franck, F. (1951) Der Einfluß des Lichtes auf die geotropische Reaktion. Inaugural dissertation, Eberhard-Karls-Universität Tübingen
Fukshansky, L. (1981) A quantitative study of timing in plant photoperiodism. J. Theor. Biol. 93, 63–91
Gierer, A. (1981) Generation of biological patterns and form: some physical, mathematical, and logical aspects. Prog. Biophys. Mol. Biol. 37, 1–47
Green, P.B. (1985) Surface of the shoot apex: reinforcement-field theory for phyllotaxis. J. Cell Sci., Suppl. 2, 181–201
Hild, V. (1977) Wirkung von Vorbestrahlung mit Rot-oder Blaulicht auf die geotropische Empfindlichkeit von Maiskoleoptilen. Planta 133, 309–314
Haupt, W. (1957) Die Induktion der Polarität bei der Spore von Equisetum. Planta 49, 61–90
Hofmann, E., Schäfer, E. (1987) Red-light induced shift of the fluence-response curve for first positive curvature of maize coleoptiles. Plant Cell Physiol. 28, 37–45
Iino, M. (1987) Kinetic modelling of phototropism in maize coleoptiles. Planta 171, 110–126
Iino, M. (1988) Pulse-induced phototropism in oat and maize coleoptiles. Plant Physiol. 88, 823–828
Kunzelmann, P., Schäfer, E. (1985) Phytochrome-mediated phototropism in maize mesocotyls. Relation between light and Pfr gradients, light growth response and phototropism. Planta 165, 424–429
Kunzelmann, P., Iino, M., Schäfer, E. (1988) Phototropism of maize coleoptiles. Influence of light gradients. Planta 176, 212–220
Meyer, A.M. (1969) Versuche zur Trennung von 1. positiver und negativer Krümmung der Avenakoleoptile. Z. Pflanzenphysiol. 60, 135–146
Mohr, H. (1972) Lectures on photomorphogenesis. Springer, Heidelberg Berlin New York
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
Nick, P., Sailer, H., Schäfer, E. (1990) On the relation between photo-and gravitropically induced spatial memory in maize coleoptiles. Planta 181, 385–392
Pickard, B.G. (1972) Geotropic response pattern of the Avena coleoptile. I. Dependence on angle and duration of stimulation. Can. J. Bot. 51, 1003–1021
Sachs, T. (1984) Control of cell pattern in plants. In: Pattern formation, pp. 367–391, Malacinski, G.M., Bryant, S.V., eds. Macmillan, London New York
Sailer, H., Nick, P., Schäfer, E. (1990) Inversion of gravitropism by symmetric blue light on the clinostat. Planta 180, 378–382
Weisenseel, M.H. (1979) Induction of polarity. In: Encyclopedia of plant physiology, N.S., vol. 7: Physiology of movements, pp. 485–505, Haupt, W., Feinleib, M.E., eds. Springer, Berlin Heidelberg New York
Wiener, R. (1963) Kybernetik. Econ, Düsseldorf Wien
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This work was supported by the Deutsche Forschungsgemeinschaft and a grant of the Studienstiftung des Deutschen Volkes to P.N. The authors thank Professor Rainer Hertel (Institut für Biologie III, Albert-Ludwigs-University, Freiburg, FRG) for valuable discussions and critical reading of the manuscript.
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Nick, P., Schäfer, E. Induction of transverse polarity by blue light: An all-or-none response. Planta 185, 415–424 (1991). https://doi.org/10.1007/BF00201066
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DOI: https://doi.org/10.1007/BF00201066