Abstract
At concentrations inhibitory to the elongation of corn (Zea mays L.) roots, the auxins, indole-3-acetic acid (IAA) and α-naphthaleneacetic acid (α-NAA), cause an increase in the pH of the bathing medium; this increase occurs with an average latent period shorter than the latent period for the inhibitory effect of these auxins on elongation. Indole-2-carboxylic acid, an inactive structural analogue of IAA, and β-naphthaleneacetic acid, an inactive analogue of α-NAA, affect neither growth nor the pH of the medium. Since acid pH is known to promote and basic pH to inhibit root elongation, the data are consistent with the hypothesis that hormone-induced modification of cell-wall pH plays a role in the control of elongation of roots, as has been proposed for elongation of stems and coleoptiles.
Abbreviations
- IAA:
-
indole-3-acetic acid
- α-NAA:
-
α-naphthaleneacetic acid
- β-NAA:
-
β-naphthaleneacetic acid
References
Edwards, K.L., Scott, T.K. (1974) Rapid growth responses of corn root segments: Effect of pH on elongation. Planta119, 27–37
Evans, M.L. (1976) A new sensitive root auxanometer: Preliminary studies of the interaction of auxin and acid pH in the regulation of intact root elongation. Plant Physiol.58, 599–601
Evans, M.L., Vesper, M.J. (in press) An improved method for detecting auxin-induced hydrogen ion efflux from corn coleoptile segments. Plant Physiol.
McBride, R., Evans, M.L. (1977) Auxin inhibition of acid- and fusicoccin-induced elongation in lentil roots. Planta136, 97–102
Moloney, M.M., Cleland, R., Elliott, M.C. (1979) The acid-growth theory and the regulation of maize root growth. (Abstract) Plant Physiol. [Suppl.]63, 23
Pilet, P.E., Elliott, M.C., Moloney, M.M. (1979) Endogenous and exogenous auxin in the control of root growth. Planta146, 405–408
Rayle, D.L., Cleland, R.E. (1977) Control of plant cell enlargement by hydrogen ions. Curr. Top. Dev. Biol.11, 187–214
Thimann, K.V. (1936) Auxins and the growth of roots. Am. J. Bot.23, 561–599
Thimann, K.V. (1937) On the nature of inhibitions caused by auxin. Am. J. Bot.24, 407–412
Weisenseel, M.H., Dorn, A., Jaffe, L. (1979) Natural H+ currents traverse growing roots and root hairs of barley (Hordeum vulgare L.). Plant Physiol.64, 512–518
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Evans, M.L., Mulkey, T.J. & Vesper, M.J. Auxin action on proton influx in corn roots and its correlation with growth. Planta 148, 510–512 (1980). https://doi.org/10.1007/BF02395322
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02395322