Summary
An analysis of the pattern of movement of 14C-labelled flag leaf assimilates in wheat (Triticum aestivum l. c.v. Gabo) during grain development, indicated that the greater the requirement for assimilates by the ear the more rapid was the speed of movement of these through the peduncle to the ear and also the lower their concentration. Experiments with [14C] indoleacetic acid ([14C]IAA) suggested that auxin production by the grains was not responsible for the control of assimilate translocation through the peduncle. Limiting the supply of available assimilates by shading the lower parts of the plant, did not significantly alter the speed of movement of 14C-photosynthate through the peduncle, while severing half of the vascular tissue in the peduncle altered the pattern of movement of 14C to the ear and enhanced the speed of movement of 14C through the remaining functional conducting tissue. These results are discussed in relation to the mechanism of translocation.
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References
Crafts, A.S., Crisp, C.E.: Phloem transport in plants. San Francisco: Freeman 1971
Evans, L.T., Wardlaw, I.F.: Independent translocation of 14C-labelled assimilates and of the floral stimulus in Lolium temulentum. Planta (Berl.) 68, 310–326 (1966)
Evert, R.F., Escherich, W., Eichhorn, S.E.: Sieve plate pores in leaf veins of Hordeum vulgare. Planta (Berl.) 100, 262–267 (1971)
Fischer, K.S., Wilson, G.L.: Studies of grain producion in Sorghum bicolor (L. Moench). III The relative importance of assimilate supply, grain growth capacity and transport system. Aust. J. Agric. Res. 26, 11–23 (1975)
Geiger, D.R., Giaquinta, R.T., Sovonick, S.A., Fellows, R.J.: Solute distribution in sugar beet leaves in relation to phloem loading and translocation. Plant Physiol. 52, 585–589 (1973)
Giaquinta, R.T., Geiger, D.R.: Mechanism of inhibition of translocation by localized chilling. Plant Physiol. 51, 372–377 (1973)
Goldsmith, M.H., Cataldo, D.A., Karn, J., Brenneman, T., Trip, P.: The rapid non-polar transport of auxin in the phloem of intact Coleus plants. Planta (Berl.) 116, 301–317 (1974)
Hartt, C.E., Kortschak, H.P.: Sugar gradients and translocation of sucrose in detached blades of sugar cane. Plant Physiol. 39, 460–474 (1964)
Mason, T.G., Maskell, E.J.: Studies on the transport of carbohydrates in the cotton plant. II. The factors determining the rate and the direction of movement of sugars. Ann. Bot. 42, 571–636 (1928)
Moorby, J., Troughton, J.H., Currie, B.G.: Investigations of carbon transport in plants. II. The effects of light and darkness and sink activity on translocation. J. exp. Bot. 25, 937–944 (1974)
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 (Ber.) 110, 173–182 (1973)
Morse, R.N., Evans, L.T.: Design and development of CERES, an Australian phytotron. J. Agric. Engng. Res. 7, 128–140 (1962)
Patrick, J.W.: Vascular system of the stem of the wheat plant. II. Mature state. Aust. J. Bot. 20, 49–63 (1972)
Patrick, J.W., Wareing, P.F.: Auxin-promoted transport of metabolites in stems of Phaseolus vulgaris L. J. exp. Bot. 24, 1158–1171 (1973)
Scott, T.K., Briggs, W.R.: Auxin relationships in the Alaska pea (Pisum sativum). Amer. J. Bot. 47, 492–499 (1960)
Seth, A.K., Wareing, P.F.: Hormone-directed transport of metabolites and its possible role in plant senescence. J. exp. Bot. 18, 65–77 (1967)
Sheldrake, A.R.: Polar auxin transport in leaves of monocotyledons. Nature 238, 352–353 (1972)
Singh, A.P., Srivastava, L.M.: The fine structure of corn phloem. Canad. J. Bot. 50, 839–846 (1972)
Thimann, K.V., Wardlaw, I.F.: The effect of light on the uptake and transport of indoleacetic acid in the green stem of the pea. Physiol. Plant. 16, 368–377 (1963)
Tyree, M.T., Christy, A.L., Ferrier, J.M.: A simpler iterative steady state solution of Münch pressure flow systems applied to long and short translocation paths. Plant Physiol. 54, 589–600 (1974)
Vardar, Y., (Ed.): The transport of plant hormones. Amsterdam: North-Holland Publ. Co. 1968
Wardlaw, I.F.: The velocity and pattern of assimilate translocation in wheat plants during grain development. Aust. J. biol. Sci. 18, 269–281 (1965)
Wardlaw, I.F.: Phloem transport: Physical, chemical, or impossible. Ann. Rev. Plant Physiol. 25, 515–539 (1974a)
Wardlaw, I.F.: Temperature control of translocation. In: “Mechanisms of regulation of plant growth”. pp. 533–538. Ed.: R.L. Bieleski, A.R. Ferguson, M.M. Cresswell. Bull. 12, Roy. Soc., N.Z. (1974b)
Wheeler, A.W.: Changes in growth-substance contents during growth of wheat grains. Ann. Appl. Biol. 72, 327–334 (1972)
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Wardlaw, I.F., Moncur, L. Source, sink and hormonal control of translocation in wheat. Planta 128, 93–100 (1976). https://doi.org/10.1007/BF00390309
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DOI: https://doi.org/10.1007/BF00390309