Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-18T16:45:39.037Z Has data issue: false hasContentIssue false

Effect of ammonium on the regulation of sodium transport in Helianthus annuus

Published online by Cambridge University Press:  27 March 2009

S. M. Ragab
Affiliation:
Soils Department, Faculty of Agriculture, University of Al Azhar, Cairo, Egypt

Summary

The electrical potential difference between exuding sap of detopped sunflower plants and rooting media containing different NH4 ion concentrations was measured, together with the Na and K concentrations in root tissue and their fluxes in the xylem exudate. It was found that adding NH4 ions to the medium made the electrical potential difference less negative with respect to the external solution and decreased the water conductivity of roots. Moreover, fewer K and Na ions were transported to the xylem sap and the K concentration in root tissue after 3 h had decreased whereas that of Na had increased. These results suggest that the sunflower root acts as an efficient accumulator for Na rather than simply as a barrier to Na transport. It is suggested that NH4 ions caused a decrease in charge separation across one of the barriers where Na is actively transported so that adding NH4 ions to the medium increased Na accumulation in root cells. This barrier may have been at the symplast.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1979

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ansari, A. Q. & Bowling, D. J. F. (1972). The effect of water and salt fluxes on the trans-root potential in Helianthus annuus. Journal of Experimental Botany 23, 641650.CrossRefGoogle Scholar
Bowling, D. J. F. (1976). Uptake of Ion in Plant Boots, pp. 5272. London: Chapman and Hall.Google Scholar
Bowling, D. J. F. & Ansaki, A. Q. (1971). Evidence for a sodium influx pump in sunflower roots. Planta (Berlin) 98, 323329.CrossRefGoogle ScholarPubMed
Brouwer, R. (1965). Ion absorption and transport in plants. Annual Review of Plant Physiology 1, 241266.CrossRefGoogle Scholar
Collandeb, R. (1941). Selective absorption of cations by higher plants. Plant Physiology, Lancaster 16, 691720.CrossRefGoogle Scholar
Epstein, E. (1966). Dual pattern of ion absorption by plant cells and by plants. Nature, London 212, 13241327.CrossRefGoogle Scholar
Epstein, E. (1969). Mineral metabolism of halophytea. In Ecological Aspects of the Mineral Nutrition in Plants, ed. Rorison, I. H., pp. 345355. Philadelphia: Blackwell.Google Scholar
Epstein, E. & Hagen, C. E. (1952). A kinetio study of the absorption of alkali cations by barley roots. Plant Physiology, Lancaster 27, 457474.CrossRefGoogle ScholarPubMed
Evans, E. G. & Vatjghan, B. E. (1966). New method for effecting watertight seals on corn roots. Plant Physiology, Lancaster 41, 10771078.CrossRefGoogle ScholarPubMed
Fatjst, H. (1960). Untersuchungen uber die mineral-stoffabgabe veinjahriger pflanzen. Zeitschrift Pflanzenerndhr ung fur Dungung und Bodenk unde 90, 8393.Google Scholar
Gauch, H. G. & Wadleigh, C. H. (1945). Effect of high concentrations of sodium, calcium, chloride and sulfate on ionic absorption by bean plants. Sail Science 59, 139153.CrossRefGoogle Scholar
Higlnbotham, N. (1973). Electropotentials of plant cells. Annual Review of Plant Physiology 24, 2546.CrossRefGoogle Scholar
Hotfaker, R. C. & Wallace, A. (1959). Effect of potassium and sodium levels on sodium distribution in some plant species. Soil Science 88, 8082.Google Scholar
Jacoby, B. (1964). Function of bean roots and stems in sodium retention. Plant Physiology, Lancaster 39, 445449.CrossRefGoogle ScholarPubMed
Jaegere, R., De Lesaint, C. & Coic, Y. (1963). Sur l'excretion d'ions mineraux: influence du changement de nature de l'alimentation azotee. Annales de Physiologie Vegetate, Paris 4, 263276.Google Scholar
Kragmann, D. V., Jagenndobf, A. T. & Avron, M. (1959). Uncouplers of spinach chloroplast photosynthesis phosphorylation. Plant Physiology, Lancaster 34, 272277.CrossRefGoogle Scholar
Maeschner, H. & Schafarczyk, W. (1967). Influx und efflux von natrium und kalium bei mais- und zuckerrubenpflanzen. Zeitschrift fur Pflanznernahrung fur Dungung und Bodenkunde 118, 187201.CrossRefGoogle Scholar
Pabr, J. F. & Norman, A. G. (1963). A procedure for control of pH in cation uptake studies with excised barley roots. Soil Science Society American Proceedings 27, 531534.Google Scholar
Paeb, J. F. & Norman, A. G. (1964). pH control in nitrate uptake studies with excised roots. Plant and Soil 213, 185190.Google Scholar
Pearson, G. A. (1967). Absorption and translocation of sodium in beans and cotton. Plant Physiology, Lancaster 42, 11711175.CrossRefGoogle ScholarPubMed
Pitman, M. G. (1965). Sodium and potassium uptake by seedlings of Hordeum vulgare. Australian Journal of Biological Science 18, 1024.CrossRefGoogle Scholar
Pitman, M. G., Cotjbtice, A. C. & Lee, B. (1968). Comparison of potassium and sodium uptake by barley roots at high and low salt status. Australian Journal of Biological Science 21, 871881.CrossRefGoogle Scholar
Puritch, G. S. & Barker, A. V. (1967). Structure and function of tomato leaf chloroplasts during ammonium toxicity. Plant Physiology, Lancaster 42, 12291238.CrossRefGoogle ScholarPubMed
Shone, M. G. T. (1968). Electrochemical relations in the transfer of ions to the xylem sap of maize roots. Journal of Experimental Botany 19, 468485.CrossRefGoogle Scholar
Shone, M. G. T. (1969). Origins of the electrical potential difference between the xylem sap of maize roots and the external solution. Journal of Experimental Botany 20, 689716.CrossRefGoogle Scholar
Shone, M. G. T., Clarkson, D. T. & Sanderson, J. (1969). The absorption and translocation of sodium by maize seedlings. Planta (Berlin) 86, 301314.CrossRefGoogle ScholarPubMed
Stuart, D. M. & Haddock, J. L. (1968). Inhibition of water uptake in sugar beet roots by ammonia. Plant Physiology, Lancaster 43, 345350.CrossRefGoogle ScholarPubMed