Abstract
Water-stress conditions were applied to the apical 12 mm of intact or excised roots ofZea mays L. (cv. LG 11) using mannitol solutions (0 to 0.66 M) and changes in weight, water content, growth and IAA level of these roots were investigated. With increasing stress a decrease in growth, correlated with an increased IAA level, was observed. The largest increase in IAA (about 2.7-fold) was found in the apical 5 mm of the root and was obtained under a stress corresponding to an osmotic potential of −1.39 MPa in the solution. This stress led to an isotonic state in the cells after 1 h. When the duration of water stress (−1.09 MPa) was increased to 2 or 3 h, no further increase in the IAA content was observed in the root segments. This indicated that there was no correlation between a hypothetical passive penetration of mannitol in the cells and IAA content. Indol-3yl-acetic acid rose to the same level in excised as in intact roots. In both cases, IAA accumulation was apparently independent of the hydrolysis of the conjugated form. The caryopsis and shoot seem not to be necessary to induce the increase of the IAA level in the roots during water stress (−1.09 MPa). Therefore, there seems to be a high rate of IAA biosynthesis in excised maize roots under water-stress conditions. Exodiffusion of IAA was observed during an immersion in either buffer or stress (−1.09 MPa) solution. In both cases, this IAA efflux into the medium represented about 50% of the endogenous level. Considering the present results, IAA appears to play an important part in the regulation of maize root metabolism and growth under water deficiency.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Abbreviations
- ABA:
-
cis-abscisic acid
References
Bourquin, M., Pilet, P.E. (1990) Effect of zeatin on the growth and indolyl-3-acetic acid and abscisic acid levels in maize roots. Physiol. Plant.80, 342–349
Bradford, K.J., Hsiao, T.C. (1982) Physiological responses to moderate water stress. In: Encyclopedia of plant physiology, vol. 12 B, pp 264–324, Lange, O.L., Nobel, P.S., Osmond, C.B., Ziegler, H., eds. Springer-Verlag, New York
Cleland, R.C. (1971) Cell wall extension. Annu. Rev. Plant Physiol.22, 197–222
Davenport, T.L., Morgan, P.W., Jordan, W.R. (1977) Auxin transport as related to leaf abscission during water stress in cotton. Plant Physiol.59, 554–557
Davies, W.J., Metcalfe, J., Lodge, T.A., da Costa, A.R. (1986) Plant growth substances and the regulation of growth under drought. Aust. J. Plant Physiol.13, 105–125
Feldman, L.J. (1980) Auxin biosynthesis and metabolism in isolated roots ofZea mays. Physiol. Plant.49, 145–150
Guinn, G., Dunlap, J.R., Brummett, D.L. (1990) Influence of water deficits on the abscisic acid and indole-3-acetic acid contents of cotton flower buds and flowers. Plant Physiol.93, 1117–1120
Hall, M.A., Kapuya, J.A., Sivakumaran, S., John, A. (1977) The role of ethylene in the response of plants to stress. Pestic. Sci.8, 217–223
Hartung, W., Witt, J. (1968) Über den Einfluß der Bodenfeuchtigkeit auf den Wuchsstoffgehalt vonAnastatica hierochuntica undHelianthus annuus. Flora157, 603–614
Hasenstein, K.H., Evans, M.L. (1988) Effects of cations on hormone transport in primary roots ofZea mays. Plant Physiol.86, 890–894
Ishizawa, K., Esashi, Y. (1984) Osmoregulation in rice coleoptile elongation as promoted by cooperation between IAA and ethylene. Plant Cell Physiol.25, 495–504
Itoh, K., Nakamura, Y., Kawata, H., Yamada, T., Ohta, E., Sakata, M. (1987) Effect of osmotic stress on turgor pressure in mung bean root cells. Plant Cell Physiol.28, 987–994
Karmoker, J.L., Van Steveninck, R.F.M. (1978) Stimulation of volume flow and ion flux by abscisic acid in excised root systems ofPhaseolus vulgaris L. cv. Redland Pioneer. Planta141, 37–43
Karmoker, J.L., Van Steveninck, R.F.M. (1979) The effect of abscisic acid on sugar levels in seedlings ofPhaseolus vulgaris L. cv. Redland Pioneer. Planta146, 25–30
Kutschera, U., Schopfer, P. (1986) In vivo measurement of cell-wall extensibility in maize coleoptiles: effects of auxin and abscisic acid. Planta169, 437–442
Kuzmanoff, K.M., Evans, M.L. (1981) Kinetics of adaptation to osmotic stress in lentil (Lens culinaris Med.) roots. Plant Physiol.68, 244–247
Lachno, D.R., Harrison-Murray, R.S., Audus, L.J. (1982) The effects of mechanical impedance to growth on the levels of ABA and IAA in root tips ofZea mays L. J. Exp. Bot.33, 943–951
Liu, Q., Katou, K., Okamoto, H. (1992) Effects of exogenous auxin on the regulation of elongation growth of excised segments ofVigna hypocotyls under osmotic stress. Plant Cell Physiol.33, 915–919
Martin, H.V., Elliott, M.C. (1984) Ontogenetic changes in the transport of indol-3yl-acetic acid into maize roots from the shoot and caryopsis. Plant Physiol.74, 971–974
Momonoki, Y.S., Schulze, A., Bandurski, R.S. (1983) Effect of deseedling on the indole-3-acetic acid content of shoots and roots ofZea mays seedlings. Plant Physiol.72, 526–529
Morgan, P.W. (1990) Effects of abiotic stresses on plant hormone systems: In: Stress responses in plants: adaptation and acclimation mechanisms, pp. 113–146, Alscher, R.G., Cumming, J.R. eds. Wiley-Liss, New York
Pernet, J.J., Pilet, P.E. (1976) Indoleacetic acid movement in the root cap. Planta128, 183–184
Pilet, P.E., Barlow, P.W. (1987) The rôle of abscisic acid in root growth and gravireaction: A critical review. Plant Growth Regul.6, 217–265
Pilet, P.E., Saugy, M. (1985) Effect of applied and endogenous indol-3-yl-acetic acid on maize root growth. Planta164, 254–258
Pilet, P.E., Saugy, M. (1987) Effect on root growth of endogenous and applied IAA and ABA. Plant Physiol.83, 33–38
Pilet, P.E., Elliott, M.C., Moloney, M.M. (1979) Endogenous and exogenous auxin in the control of root growth. Planta146, 405–408
Pilet, P.E., Versel, J.M., Mayor, G. (1983) Growth distribution and surface pH patterns along maize roots. Planta158, 398–402
Ribaut, J.M., Pilet, P.E. (1991) Effects of water stress on growth, osmotic potential and abscisic acid content of maize roots. Physiol. Plant.81, 156–162
Ribaut, J.M., Schaerer, S., Pilet, P.E. (1993) Deuterium-labelled indole-3-acetic acid neo-synthesis in plantlets and excised roots of maize. Planta189, 80–82
Saab, I.N., Sharp, R.E., Pritchard, J., Voetberg, G.S. (1990) Increased endogenous abscisic acid maintains primary root growth and inhibits shoot growth of maize seedlings at low water potentials. Plant Physiol.93, 1329–1336
Sakurai, N., Akiyama, M., Kuraishi, S. (1985) Roles of abscisic acid and indoleacetic acid in the stunted growth of water-stressed etiolated squash hypocotyls. Plant Cell Physiol.26, 15–24
Sharp, R.E., Silk, W.K., Hsiao, T.C. (1988) Growth of the maize primary root at low water potentials. I: Spatial distribution of expansive growth. Plant Physiol.87, 50–57
Torrey, J.G. (1976) Root hormones and plant growth. Annu. Rev. Plant Physiol.27, 435–459
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ribaut, J.M., Pilet, P.E. Water stress and indol-3yl-acetic acid content of maize roots. Planta 193, 502–507 (1994). https://doi.org/10.1007/BF02411554
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02411554