Plant and Soil

, Volume 352, Issue 1–2, pp 353–362 | Cite as

Interactions between Ca, Mg, Na and K: alleviation of toxicity in saline solutions

  • Peter M. Kopittke
Regular Article


Background and aims

Saline soils limit plant production worldwide through osmotic stress, specific-ion toxicities, and nutritional imbalances.


The ability of Ca2+ and K+ to alleviate toxicities of Na+ and Mg2+ was examined using 89 treatments in short-term (48 h) solution culture studies for cowpea (Vigna unguiculata (L.) Walp.) roots. Root elongation was related to ionic activities at the outer surface of the root plasma membrane.


The addition of K+ was found to alleviate the toxic effects of Na+, and supplemental Ca2+ improved growth further in these partially-alleviated solutions where K+ was present. Therefore, Na+ appears to interfere with K+ metabolism, and Ca2+ reduces this interference. Interestingly, the ability of Ca2+ to improve K-alleviation of Na+ toxicity is non-specific, with Mg2+ having a similar effect. In contrast, the addition of Ca2+ to Na-toxic solutions in the absence of K+ did not improve growth, suggesting that Ca2+ does not directly reduce Na+ toxicity in these short-term studies (for example, by reducing Na+ uptake) when supplied at non-deficient levels. Finally, K+ did not alleviate Mg2+ toxicity, suggesting that Mg2+ is toxic by a different mechanism to Na+.


Examination of how the toxic effects of salinity are alleviated provides clues as to the underlying mechanisms by which growth is reduced.


Alleviation of toxicity Root growth Salinity Specific-ion toxicity 



The author thanks Neal Menzies, Pax Blamey, and Brigid McKenna for their assistance and discussions. This research was funded through the Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC-CARE) Project 3-03-05-09/10. The support of the Environment Protection Authority (EPA) Victoria is also acknowledged.

Supplementary material

11104_2011_1001_MOESM1_ESM.pdf (142 kb)
Supplementary Table S1-S3 Compositions of solutions used in Experiments 1–3. (PDF 141 kb)


  1. Bell RW, Edwards DG, Asher CJ (1989) External calcium requirements for growth and nodulation of six tropical food legumes grown in flowing solution culture. Aust J Agric Res 40:85–96CrossRefGoogle Scholar
  2. Burstrom H (1953) Physiology of root growth. Annu Rev Plant Physiol 4:237–252CrossRefGoogle Scholar
  3. Cakmak I (2005) The role of potassium in alleviating detrimental effects of abiotic stresses in plants. J Plant Nutr Soil Sci 168:521–530CrossRefGoogle Scholar
  4. Cramer G (2002) Sodium-calcium interactions under salinity stress. In: Läuchli A, Lüttge U (eds) Salinity: environment - plants - molecules. Springer, Dordrecht, pp 205–227Google Scholar
  5. Cramer GR, Läuchli A, Polito VS (1985) Displacement of Ca2+ by Na+ from the plasmalemma of root cells. Plant Physiol 79:207–211PubMedCrossRefGoogle Scholar
  6. del Amor FM, Marcelis LFM (2003) Regulation of nutrient uptake, water uptake and growth under calcium starvation and recovery. J Hortic Sci Biotechnol 78:343–349Google Scholar
  7. Demidchik V, Tester M (2002) Sodium fluxes through nonselective cation channels in the plasma membrane of protoplasts from Arabidopsis roots. Plant Physiol 128:379–387PubMedCrossRefGoogle Scholar
  8. Flowers TJ, Flowers SA (2005) Why does salinity pose such a difficult problem for plant breeders? Agr Water Manag 78:15–24CrossRefGoogle Scholar
  9. Goldbach HE, Yu Q, Wingender R, Schulz M, Wimmer M, Findeklee P, Baluska F (2001) Rapid response reactions of roots to boron deprivation. J Plant Nutr Soil Sci 164:173–181CrossRefGoogle Scholar
  10. Grattan SR, Grieve CM (1999) Mineral nutrient aquisition and response by plants grown in saline environments. In: Pessarakli M (ed) Handbook of plant and crop stress. Marcel Dekker, New York, pp 203–229Google Scholar
  11. Greenway H, Munns R (1980) Mechanisms of salt tolerance in nonhalophytes. Annu Rev Plant Physiol 31:149–190CrossRefGoogle Scholar
  12. Grieve CM, Fujiyama H (1987) The response of two rice cultivars to external Na/Ca ratio. Plant Soil 103:245–250CrossRefGoogle Scholar
  13. Grieve CM, Maas EV (1988) Differential effects of sodium/calcium ratio on sorghum genotypes. Crop Sci 28:659–665CrossRefGoogle Scholar
  14. Kinraide TB (1998) Three mechanisms for the calcium alleviation of mineral toxicities. Plant Physiol 118:513–520PubMedCrossRefGoogle Scholar
  15. Kinraide TB (1999) Interactions among Ca2+, Na+ and K+ in salinity toxicity: quantitative resolution of multiple toxic and ameliorative effects. J Exp Bot 50:1495–1505CrossRefGoogle Scholar
  16. Kinraide TB (2001) Ion fluxes considered in terms of membrane-surface electrical potentials. Aust J Plant Physiol 28:607–618Google Scholar
  17. Kinraide TB (2006) Plasma membrane surface potential (ψPM) as a determinant of ion bioavailability: a critical analysis of new and published toxicological studies and a simplified method for the computation of plant ψPM. Environ Toxicol Chem 25:3188–3198PubMedCrossRefGoogle Scholar
  18. Kinraide TB, Parker DR (1987) Cation amelioration of aluminum toxicity in wheat. Plant Physiol 83:546–551PubMedCrossRefGoogle Scholar
  19. Kinraide TB, Wang P (2010) The surface charge density of plant cell membranes (σ): an attempt to resolve conflicting values for intrinsic σ. J Exp Bot 61:2507–2518PubMedCrossRefGoogle Scholar
  20. Kopittke PM, Blamey FPC, Menzies NW (2008) Toxicities of soluble Al, Cu, and La include ruptures to rhizodermal and root cortical cells of cowpea. Plant Soil 303:217–227CrossRefGoogle Scholar
  21. Kopittke PM, Blamey FPC, Kinraide TB, Wang P, Reichman SM, Menzies NW (2011) Separating multiple, short-term deleterious effects of saline solutions to the growth of cowpea seedlings. New Phytol 189:1110–1121PubMedCrossRefGoogle Scholar
  22. Leigh RA, Wyn Jones RG (1984) A hypothesis relating critical potassium concentrations for growth to the distribution and functions of this ion in the plant-cell. New Phytol 97:1–13CrossRefGoogle Scholar
  23. Lindsay WL (1979) Chemical equilibria in soils. Wiley, New York, p 449Google Scholar
  24. Munns R (2002) Comparative physiology of salt and water stress. Plant Cell Environ 25:239–250PubMedCrossRefGoogle Scholar
  25. Munns R (2011) Plant adaptations to salt and water stress: differences and commonalities. In: Turkan I (ed) Plant responses to drought and salinity stress: developments in a post-genomic era, pp 1–32Google Scholar
  26. Nakamura Y, Tanaka K, Ohta E, Sakata M (1990) Protective effect of external Ca2+ on elongation and the intracellular concentration of K+ in intact mung bean roots under high NaCl stress. Plant Cell Physiol 31:815–821Google Scholar
  27. NLWRA (2002) Australians and natural resource management, National Land and Water Resources Audit, Canberra
  28. Pitman MG, Läuchli A (2002) Global impact of salinity and agricultural ecosystems. In: Läuchli A, Lüttge U (eds) Salinity: environment - plants - molecules. Kluwer Academic, Dordrecht, pp 3–20Google Scholar
  29. Ryan PR, Delhaize E, Randall PJ (1995) Characterisation of Al-stimulated efflux of malate from the apices of Al-tolerant wheat roots. Planta 196:103–110CrossRefGoogle Scholar
  30. Schmidt C, He T, Cramer GR (1993) Supplemental calcium does not improve growth of salt-stressed Brassicas. Plant Soil 155–156:415–418CrossRefGoogle Scholar
  31. Shabala S, Cuin TA (2008) Potassium transport and plant salt tolerance. Physiol Plant 133:651–669PubMedCrossRefGoogle Scholar
  32. Shabala S, Shabala L, Van Volkenburgh E, Newman I (2005) Effect of divalent cations on ion fluxes and leaf photochemistry in salinized barley leaves. J Exp Bot 56:1369–1378PubMedCrossRefGoogle Scholar
  33. Taylor GJ, Stadt KJ, Dale MRT (1991) Modeling the phytotoxicity of aluminum, cadmium, copper, manganese, nickel, and zinc using the Weibull frequency-distribution. Can J Bot 69:359–367CrossRefGoogle Scholar
  34. Tester M, Davenport R (2003) Na+ tolerance and Na+ transport in higher plants. Ann Bot 91:503–527PubMedCrossRefGoogle Scholar
  35. Wang SM, Zhang JL, Flowers TJ (2007) Low-affinity Na+ uptake in the halophyte Suaeda maritima. Plant Physiol 145:559–571PubMedCrossRefGoogle Scholar
  36. Wang KS, Huang LC, Lee HS, Chen PY, Chang SH (2008) Phytoextraction of cadmium by Ipomoea aquatica (water spinach) in hydroponic solution: effects of cadmium speciation. Chemosphere 72:666–672PubMedCrossRefGoogle Scholar
  37. Wang P, Kinraide TB, Zhou DM, Kopittke PM, Peijnenburg WJGM (2011) Plasma membrane surface potential: dual effects upon ion uptake and toxicity. Plant Physiol 155:808–820PubMedCrossRefGoogle Scholar
  38. Yermiyahu U, Kinraide TB (2005) Binding and electrostatic attraction of trace elements to plant-root surfaces. In: Huang PM, Gobran GR (eds) Biogeochemistry of trace elements in the rhizosphere. Elsevier, Amsterdam, pp 365–389CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  1. 1.School of Agriculture and Food SciencesThe University of QueenslandSt. LuciaAustralia
  2. 2.Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC-CARE)The University of QueenslandSt. LuciaAustralia

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