Summary
In this short survey differences between species and varieties in the four major mechanisms that affect selective uptake of potassium and sodium to the plant within the root are considered. These include influx selectivity, K+/Na+ exchange at the plasmalemma, and selectivity at the tonoplast as well as at the symplasm-xylem boundary. The affinity of various plants for potassium influx in system 1 is rather uniform although varietal differences in barley have been observed. Differences are much more pronounced for sodium influx, for which Helianthus showed rather high and Fagopyrum rather low affinity. There is substantial variation between species in the efficiency of K+/Na+ exchange at the plasmalemma of cortical root cells; the three cereals Hordeum, Triticum, and Secale were highly efficient while K+/Na+ exchange in Atriplex, Helianthus and Allium was poor, even if the cytoplasmic sodium content was accounted for. Apparently there was no direct relation between salt tolerance and K+/Na+ exchange. The observed differences in the efficiency of K+-dependent sodium extrusion or K+/Na+ exchange were not due to the use of excised roots, they were observed also when roots of whole seedlings were investigated. At the tonoplast a 1:1 exchange of vacuolar potassium for sodium has been observed in roots of Hordeum. By this exchange sodium ions are removed from the symplasm and potassium ions are recovered from vacuoles and thus made available for transport to the shoot. Indications for specific differences in this exchange have been observed; the exchange appears to be more efficient in Helianthus than in Hordeum roots. More comparative studies are needed here. At the boundary between symplasm and xylem vessels selectivity can be set up during xylem release of cations and there are reports that suggest a preference for sodium (Lycopersicum cheesemanii, Solanum pennellii, and Suaeda) and for varietal differences amongst tomatoes. Selectivity at this boundary, the plasmalemma of the xylem parenchyma cells was described in this paper by the selectivity ratio of transport that relates the rates of xylem transport to the cytoplasmic sodium and potassium concentrations. Based on this ratio Atriplex hortensis was shown to discriminate for sodium during xylem release while there was little selectivity in Hordeum and possibly some discrimination in favour of K+ in Allium roots. The data are shortly discussed in relation to salt tolerance and to the breeding of salt-tolerant crop varieties.
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References
Collander R 1941 Selective absorption of cations by higher plants. Plant Physiol. 16, 691–721.
Dehan K and Tal M 1978 Salt tolerance in the wild relatives of the cultivated tomato: Responses of Solanum pennellii to high salinity. Irrig. Sci. 1, 71–76.
Dewey D R 1962 Breeding crested wheatgrass for salt tolerance. Crop Sci. 2, 403–407.
Epstein E 1972 Mineral Nutrition of Plants: Principles and Perspectives. Wiley, New York.
Epstein E 1976 In Encyclopedia of Plant Physiology, New Series Eds. U. Lüttge and M. G. Pitman. Springer-Verlag, Berlin—Heidelberg—New York Vol 2B pp 70–94.
Erlandson G 1979 Flux of potassium from wheat roots induced by changes in the water potential of the root medium. Physiol. Plant. 47, 1–6.
Flowers T J, Troke P F and Yeo A R 1977 The mechanism of salt tolerance in halophytes. Annu. Rev. Plant Physiol. 28, 89–121.
Glass A D M 1978 The regulation of potassium influx into intact roots of barley by internal potassium levels. Can. J. Bot. 56, 1759–1764.
Glass A D M and Perley J E 1980 Varietal differences in potassium uptake by barley. Plant Physiol. 65, 160–164.
Glass A D M, Siddiqi M Y and Giles K I 1981 Correlations between potassium uptake and hydrogen efflux in barley varieties. 68, 457–459.
Greenway H 1962 Plant response to saline substrates. II. Chloride, sodium, and potassium uptake and translocation in young plants of Hordeum vulgare during and after a short sodium chloride treatment. Aust. J. Biol. Sci. 15, 39–57.
Greenway H and Munns R 1980 Mechanisms of salt tolerance in nonhalophytes. Annu. Rev. Plant Physiol. 31, 149–190.
Jacoby B 1965 Sodium retention in excised bean stems. Physiol. Plant. 18, 730–739.
Jefferies R L 1973 The ionic relations of seedlings of the halophyte Triglochin maritima L. In Ion transport in Plants. Ed. W P Anderson. Academic Press, London-New York. pp 297–321.
Jensen P and Kylin A 1980 Effects of ionic strength and relative humidity on the efflux of K+ (86Rb) and Ca++ (45Ca) from roots of intact seedlings of cucumber, oat, and wheat. Physiol. Plant. 50, 199–207.
Jeschke W D 1972 Wirkung von K+ auf die Fluxe und den Transport von Na+ in Gersten wurzeln, K+-stimulierter Na+-Efflux in der Wurzelrinde. Planta, Berlin 106, 73–90.
Jeschke, W D 1973 K+-stimulated Na+ efflux and selective transport in barley roots. Ref. Jefferies pp 285–296.
Jeschke, W D 1977 K+ — Na+ selectivity in roots. Localization of the selective fluxes and their regulation. In Regulation of Cell Membrane Activities in Plants. Eds. E Marrè and O Cifferi. Elsevier Amsterdam pp 63–78.
Jeschke W D 1977 K+ — Na+ Exchange and selectivity in barley root cells. Effect of Na+ on the Na+ fluxes. J. Exp. Bot. 28, 1289–1305.
Jeschke W D 1979 Univalent cation selectivity and compartmentation in cereals. In Recent Advances in the Biochemistry of Cereals. Eds. D L Laidman and R G Wyn Jones. Academic Press, London-New York. pp 37–61.
Jeschke W D 1980 Involvement of proton fluxes in the K+— Na+ selectivity at the plasmalemma; K+-dependent net extrusion of sodium in barley roots and the effect of anions and pH on sodium fluxes. Z. Pflanzenphysiol. 98, 155–75.
Jeschke W D 1982 Shoot-dependent regulation of sodium and potassium fluxes in roots of whole barley seedlings. J Exp. Bot. 33, 601–619.
Jeschke W D and Jambor W 1981 Determination of unidirectional sodium fluxes in roots of intact sunflower seedlings. J. Exp. Bot. 32, 1257–1272.
Jeschke W D and Nassery H 1981 K+ — Na+ selectivity in roots of Triticum, Helianthus and Allium. Physiol. Plant. 52, 217–224.
Jeschke W D and Stelter W 1976 Measurement of longitudinal ion profiles in single roots of Hordeum and Atriplex by use of flameless atomic absorption spectroscopy. Planta, Berlin 128, 107–112.
Läuchli A and Wieneke J 1979 Studies on growth and distribution of Na+, K+ and Cl- in soybean varieties differing in salt tolerance. Z. Pflanzenernaehr. Bodenkd. 142, 3–13.
Maas E V and Nieman R H 1978 Physiology of plant tolerance to salinity. In Crop Tolerance to Suboptimal Land Conditions. Ed. G A Jung. Am. Soc. Agron. Spec. Publ. 32, 277–299.
Macklon A E S 1975 Cortical cell fluxes and transport to the stele in excised root segments of Allium cepa L. I. Potassium, sodium and chloride. Planta, Berlin 122, 109–130.
Neirinckx L J A and Bange G G J 1971 Irreversible equilibration of barley roots with Na+ ions at different external Na+ concentrations. Acta Bot. Neerl. 20, 481–488.
Picciuro G and Brimetti N 1969 Assorbimento del sodio (22Na) in radici escisse di alcune varietà di Lycopersicum esculentum. Agrochimica 13, 347–57.
Pierce W S and Higinbotham N 1970 Compartmentation and fluxes of K+, Na+ and Cl- in Avena coleoptile cells. Plant Physiol. 46, 666–673.
Pitman M G 1965 Sodium and potassium uptake by seedlings of Hordeum vulgare. Aust. J. Biol. Sci. 18, 10–24.
Pitman M G, Läuchli A and Stelzer R 1981 Ion distribution in roots of barley seedlings measured by electron probe X-ray microanalysis. Plant Physiol. 68, 673–679.
Pitman M G and Saddler H D W 1967 Active sodium and potassium transport in cells of barley roots. Proc. Nat. Acd. Sci. (Wash.) 57, 44–49.
Rains H D W and Epstein E 1967 Sodium absorption by barley roots: Its mediation by mechanism 2 of alkali cation transport. Plant Physiol. 42, 319–323.
Ratner A and Jacoby B 1976 Effect of K+, its counter anion, and pH on sodium efflux from barley root tips. J. Exp. Bot. 27, 843–852.
Rush D W and Epstein E 1976 Genotypic responses to salinity: differences between salt-sensitive and salt-tolerant genotypes of the tomato. Plant Physiol. 57, 162–166.
Rush D W and Epstein E 1981 Comparative studies on the sodium, potassium, and chloride relations of a wild halophytic and a domestic salt-sensitive tomato species. Plant Physiol. 68, 1308–1313.
Shone M G T, Clarkson D T and Sanderson J 1969 The absorption and translocation of sodium by maize seedlings. Planta 86, 301–314.
Stelter W 1979 Untersuchungen zur Kalium — Natrium — Selektivität von Atriplex hortensis L. Doctoral Thesis. University of Würzburg, Germany.
Welsh R M and Epstein E 1968 The dual mechanisms of alkali cation absorption by plant cells: their parallel operation across the plasmalemma. Proc. Nat. Acad. Sci. (Wash.) 61, 447–453.
Wyn Jones R G, Brady C J and Speirs J 1979 Ionic and osmotic relations in plant cells. Ref. Jeschke 1979. pp 64–103.
Yeo A R 1974 Salt tolerance in the halophyte Suaeda maritima L. Dum. Ph.D. Thesis, University of Sussex, England.
Zehler E 1981 Die Natriumversorgung von Mensch, Tier und Pflanze. Kalibriefe (Büntehof). 15, 773–792.
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© 1983 Martinus Nijhoff/Dr. W. Junk Publishers, The Hague
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Jeschke, W.D. (1983). Cation fluxes in excised and intact roots in relation to specific and varietal differences. In: Sarić, M.R., Loughman, B.C. (eds) Genetic Aspects of Plant Nutrition. Developments in Plant and Soil Sciences, vol 8. Springer, Dordrecht. https://doi.org/10.1007/978-94-009-6836-3_6
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