1. The specificity of the auxin transport system of suspension-cultured crown gall cells from Parthenocissus tricuspidata Planch- is examined with regard to 2,4-Dichlorophenoxyacetic acid (2,4 D), l-Naphthylacetic acid (NAA) and Benzoic acid (BA) as well as for indole-3-acetic acid (IAA). — 2. All four weak acids can be accumulated by the cells from a medium more acidic than the cytoplasm. This is by virtue of non-specific passive diffusion of their lipid-soluble protonated forms down a concentration gradient. The corresponding anionic species are much less permeant. The extent of the accumulation is dependent on the pH difference that is maintained by the cells between their cytoplasm and the incubation medium. Studies of the concentration dependence of BA and NAA net uptake at a series of external pHs suggest that an acidification of the cytoplasm can be eventually brought about by the entry of weak acid into the cells. — 3. The uptake of 2,4 D, as well as that of IAA, has a saturable carrier-mediated component in addition to the passive diffusion of the undissociated acid. These saturable components probably represent anion uptake and appear to be mediated by a common carrier. The kinetic studies provided no evidence for the participation of carriers in the transport of BA or NAA. — 4. It was shown that the efflux of 2,4 D also has a carrier-mediated component and it is suggested that both the influx and efflux of IAA and 2,4 D occur on a common carrier. — 5. The inhibitor of polar auxin transport, 2,3,5-triiodobenzoic acid (TIBA), stimulates the net uptake of IAA by inhibiting carrier-mediated efflux of IAA from the cells. However, TIBA could not be demonstrated to have a significant effect on 2,4 D transport and any perturbation that occurs is very small in comparison with its effect on IAA movement. To account for this, the proposed common carrier could exhibit some difference in its internal binding characteristics betweend 2,4 D and IAA. An alternative explanation is that a second carrier is present, which mediates IAA efflux only, and which is inhibited by TIBA. — 6. TIBA has no significant effect on the transport of either BA or NAA, except to bring about an inhibition of net uptake, and a corresponding stimulation of efflux, when it is present at concentrations sufficient to acidify the cytoplasm. —7. The crown gall cells are compared to intact plant tissues capable of polar auxin transport with regard to the specificities exhibited for the transport of the auxins IAA, 2,4 D and NAA and the non-auxin BA.
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indol-3-yl acetic acid
- 2,4 D:
Batt, S., Wilkins, M.B., Venis, M.A.: Auxin binding to corn coleoptile membranes: kinetics and specificity. Planta 130, 7–14 (1976)
Davies, D.D.: Control of and by pH. Symp. Soc. Exp. Biol. 27, 513–529 (1973)
Dixon, M.: The determination of enzyme inhibitor constants. Biochem. J. 55, 170–171 (1953)
Fisher, M.L., Albersheim, P.: Characterisation of a H+ efflux from suspension-cultured plant cells. Plant Physiol. 53, 464–468 (1974)
Hertel, R., Flory, R.: Auxin movement in corn coleoptiles. Planta 82, 123–144 (1968)
Hertel, R., Evans, M.L., Leopold, A.C., Sell, H.M.: The specificity of the auxin transport system. Planta 85, 238–249 (1969)
Jönsson, Å: Chemical structure and growth activity of auxins and antiauxins. In: Encyclopedia of Plant Physiology, vol. XIV, pp 959–1006, Ruhland, W., ed. Berlin-Heidelberg-New York: Springer 1961
Leopold, A.C., Lam, S.L.: Polar transport of three auxins. In: Plant Growth Regulation. pp. 411–418. 4th Intern. Conf. Plant Growth Regulation, Klein, R.M., ed. Ames.-Iowa State Univ. Press. 1961
McCready, C.C.: The polarity of auxin movement in segments excised from petioles of Phaseolus vulgaris L. In: Biochemistry and Physiology of plant growth substances pp. 1005–1023. 6th Intern. Conf. Plant Growth Substances, Wightman, F., Setterfield, G.; eds. Ottawa: Runge Press. 1968
McCready, C.C., Jacobs, W.P.: Movement of growth regulators in plants. II Polar transport of radioactivity from IAA-14C and 2,4 D-14C in petioles of Phaseolus vulgaris. L. New Phytol., 62, 19–34 (1963)
Raven, J.A.: Transport of indoleacetic acid in plant cells in relation to pH and electrical potential gradients, and its significance for polar IAA transport. New Phytol., 74, 163–172 (1975)
Rayle, D.L.: Auxin-induced hydrogen ion secretion in Avena coleoptiles and its implications. Planta 114, 63–73 (1973)
Rubery, P.H.: Studies on Indoleacetic acid oxidation by liquid medium from crown gall tissue culture cells: The role of malic acid and related compounds. Biochim. Biophys. Acta 261, 21–34 (1972)
Rubery, P.H., Sheldrake, A.R.: Effect of pH and surface charge on cell uptake of auxin. Nature 244, 285–288 (1973)
Rubery, P.H., Sheldrake, A.R.: Carrier-mediated auxin transport. Planta 118, 101–121 (1974)
Smith, F.A., Raven, J.A.: H+ transport and regulation of cell pH. In: Encyclopedia of Plant Physiology (NS), 2A, 317–346 (1976)
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Rubery, P.H. The specificity of carrier-mediated auxin transport by suspension-cultured crown gall cells. Planta 135, 275–283 (1977). https://doi.org/10.1007/BF00384900
- Auxin transport
- Crown gall
- Suspension culture