Abstract
The velocity and intensity of basipetal transport of 14C-labelled indol-3yl-acetic acid (IAA) applied to the apical bud of the intact pea plant were influenced by the temperature to which the stem was exposed and were not influenced by changes in the temperature of the root system when this was controlled independently between 5°C and 35°C. The velocity of transport increased steadily with temperature to a maximum in excess of 35°C and then fell sharply with further increase in temperature. The Q10 for velocity, determined from Arrhenius plots, was low (ca. 1.3). Transport intensity increased to a maximum at about 25°C (Q10=2.2) and then declined gradually with further increase in temperature. It is suggested that transport velocity and transport intensity are controlled independently.
The characteristics of auxin transport through the stem were not affected by removal of the root system, or by the withdrawl of root aeration. Labelled IAA did not pass a region of the stem cooled to about 1.0°C, or through a narrow zone of stem tissue killed by heat treatment. In the latter case the heat treatment was shown not to interfere with the upward transport of water in the xylem. Labelled IAA continued to move into, and to accumulate in, the tissues immediately above a cooled or heat-killed region of the stem. It was concluded that the long-distance basipetal transport of auxin through the stem of the intact plant is driven by the transporting cells themselves and is independent of the activity of sinks for the transported auxin.
The fronts of the observed tracer profiles in the stem were closely fitted by error function diffusion analogue curves. However, diffusion of IAA alone could not account for the observed characteristics of the transport and it is suggested that the curvilinear fronts of the profiles resulted from a diffusive mixing of exogenous IAA (or IAA-carrier complexes) with endogenous IAA already in the transport pathway.
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Abbreviations
- IAA:
-
indol-3yl-acetic acid
- IAAsp:
-
indol-3yl-acetyl aspartic acid
- CFM:
-
methyl 2-chloro-9-hydroxyfluorene-9-carboxylate (morphactin)
- TIBA:
-
2,3,5-triiodobenzoic acid
- ABA:
-
abscisic acid
References
Bonnemain, J.-L.: Transport et distribution des traceurs après application de AIA-2-14C sur les feuilles de Vicia faba. C.R. Acad. Sci. (Paris) D273, 1699–1702 (1971)
Bourbouloux, A., Bonnemain, J.L.: Transport, distribution et métabolisme de l'auxine dans la racine de Vicia faba L. après application de [14C]AIA ou de [3H]AIA sur le bourgeon. Planta 119, 169–182 (1974)
Burg, S.P., Burg, E.A.: Inhibition of polar auxin transport by ethylene. Plant Physiol. 42, 1224–1228 (1967)
Canny, M.J.: Phloem translocation. Cambridge: University Press 1973
Chang, Y.-P., Jacobs, W.P.: The contrast between active transport and diffusion of indole-3-acetic acid in Coleus petioles. Plant Physiol. 50, 635–639 (1972)
Fry, S.C., Wangermann, E.: Polar transport of auxin through embryos. New Phytol. 77, 313–317 (1976)
Gagianas, A.A., Berg, A.R.: The effect of morphactin (methyl 2-chloro-9-hydroxyfluorene-9-carboxylate) on basipetal transport of indol-3ylacetic acid in hypocotyl sections of Phaseolus vulgaris L. Ann. Bot. 41, 1135–1148 (1977)
Goldsmith, M.H.M.: The polar transport of auxin. Annu. Rev. Plant Physiol. 28, 439–478 (1977)
Haissig, B.E.: Influence of indole-3-acetic acid on adventitious root primordia of brittle willow. Planta 95, 27–35 (1970)
Hayes, F.N.: Solutes and solvents for liquid scintillation counting. Tech. Bull. No. 1, Packard Instrument Co. Inc., Illinois 1963
Hertel, R., Leopold, A.C.: Versuche zur Analyse des Auxintransports in der Koleoptile von Zea mays L. Planta 59, 535–562 (1963)
Hollis, C.A., Tepper, H.B.: Auxin transport within intact dormant and active white ash shoots. Plant Physiol. 48, 146–149 (1971)
Kaldewey, H.: Wuchsstofftransport, Temperatur und Pflanzenalter. Ber. Dtsch. Bot. Ges. 78, 128–143 (1965)
Kaldewey, H., Ginkel, U., Lehmann, I., Seiwert, R.: Transport and immobilization of indoleacetic acid as affected by morphactins. I. Time course of auxin transport in sections excised from different hypocotyl regions of light-grown seedlings of Citrullus edulis. Trans. 3rd Symposium on accumulation and translocation of nutrients and regulators in plant organisms. Warsaw 1973
Lamb, C.J.: Hormone binding in plants. Nature (London) 274, 312–314 (1978)
Larsen, P.: Growth substances in higher plants. In: Modern methods of plant analysis, pp. 744. Paech, K., Tracey, M.V., eds. Berlin: Springer 1955
McCready, C.C.: Translocation of growth regulators. Annu. Rev. Plant Physiol. 17, 283–294 (1966)
Morris, D.A.: Transport of exogenous auxin in two-branched dwarf pea seedlings (Pisum sativum L.). Planta 136, 91–96 (1977)
Morris, D.A.: Effects of temperature on the velocity of exogenous auxin transport in intact chilling-sensitive and chilling-resistant plants. Planta 146, 603–605 (1979)
Morris, D.A., Thomas, A.G.: A microautoradiographic study of auxin transport in the stem of intact pea seedlings (Pisum sativum L.). J. Exp. Bot. 29, 147–157 (1978)
Morris, D.A., Briant, R.E., Thomson, P.G.: The transport and metabolism of 14C-labelled indoleacetic acid in intact pea seedlings. Planta 89, 178–197 (1969)
Morris, D.A., Kadir, G.O., Barry, A.J.: Auxin transport in intact pea seedlings (Pisum sativum L.). The inhibition of transport by 2,3,5-triiodobenzoic acid. Planta 110, 173–182 (1973)
Naqvi, S.M.: Transport studies with 14C indoleacetic acid and 14C 2,4-dichlorophenoxyacetic acid in Coleus stems. Ph.D. Thesis, Princetown University 1963
Naqvi, S.M.: The effect of sugar supplement on the kinetics of indoleacetic acid-2-14C transport in Zea mays coleoptile segments. Z. Pflanzenphysiol. 7, 1–5 (1974)
Naqvi, S.M., Engvild, K.C.: Action of abscisic acid on auxin transport and its relation to phototropism. Physiol. Plant. 30, 283–287 (1974)
Phillips, I.D.J.: Root-shoot hormone relations. I. The importance of an aerated root system in the regulation of growth hormone levels in the shoot of Helianthus annuus. Ann. Bot. 28, 17–35 (1964a)
Phillips, I.D.J.: Root-shoot hormone relations. II. Changes in endogenous auxin concentration produced by flooding of the root system in Helianthus annuus. Ann. Bot. 28, 36–45 (1964b)
Rowntree, R.A., Morris, D.A.: Accumulation of 14C from exogenous labelled auxin in lateral root primordia of intact pea seedlings (Pisum sativum L.). Planta 144, 463–466 (1979)
Scott, T.K., Briggs, W.R.: Auxin relationships in the Alaska pea (Pisum sativum). Am. J. Bot. 47, 492–499 (1960)
Torrey, J.G.: Root hormones and plant growth. Annu. Rev. Plant Physiol. 27, 435–459 (1976)
Veen, H., Frissel, M.J.: Simulation of hormone transport in petiole segments of Coleus. Physiol. Plant. 34, 208–215 (1975)
Wangermann, E.: The pathway of transport of applied indolylacetic acid through internode segments. New Phytol. 73, 623–635 (1974)
Weij, H.G. van der: Der Mechanismus des Wuchsstofftransportes. Rec. Trav. Bot. Neerl. 29, 379–496 (1932)
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Eliezer, J., Morris, D.A. Effects of temperature and sink activity on the transport of 14C-labelled indol-3yl-acetic acid in the intact pea plant (Pisum sativum L.). Planta 147, 216–224 (1979). https://doi.org/10.1007/BF00388741
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DOI: https://doi.org/10.1007/BF00388741