Potassium in Plants


Potassium (K) is an essential macronutrient for plants involved in many physiological processes. It is important for crop yield as well as for the quality of edible parts of crops, as it is also required in human nutrition. Although K is not assimilated into organic matter, K deficiency has a strong impact on plant metabolism. Plant responses to low K involve changes in the concentrations of many metabolites as well as alteration in the transcriptional levels of many genes and in the activity of many enzymes. Today, these changes can be studied with high throughput technologies that allow a quantitative description of metabolic responses to K deprivation at multiple levels. To ensure K nutrition, plant roots are endowed with high‐ and low‐affinity uptake systems, some of which have been identified and characterised over the last decades of research.

Key Concepts:

  • K is an essential macronutrient required for plant growth and development.

  • K deficiency affects many essential physiological and metabolic processes.

  • The K status determines the profile and distribution of primary metabolites in plant tissues.

  • K nutrition is closely related to sugar allocation, nitrogen assimilation and amino acid levels.

  • High‐throughput technologies allow researchers to determine simultaneously a large number of metabolites, transcript levels and enzyme activities in response to K supply.

  • K deficiency leads to build‐up of sugars, down‐regulation of nitrate uptake and synthesis of nitrogen‐rich amino acids.

  • Roots are endowed with high‐ and low‐affinity K uptake systems that ensure K nutrition in a wide range of external concentrations.

  • hak5 transporters mediate high‐affinity K uptake and akt1 channels mediate low‐affinity K uptake.

  • Under certain conditions akt1 channels can also mediate K uptake from very low concentrations.

  • Additional unidentified systems may also promote root K uptake.

Keywords: potassium; deficiency; metabolism; A. thaliana; uptake; abiotic stress

Figure 1.

Adequate K supply to food crops and grassland is important for many aspects of food production.

Figure 2.

The requirement of K for plant nutrition is based on many essential functions of K in plant physiology and metabolism.

Figure 3.

Example of data obtained in multi‐level analysis of the effect of K deficiency and K re‐supply on plant primary metabolism. A subset of reactions occurring in root cell cytoplasm, mitochondria and plastids of A. thaliana plants were quantified with respect to changes in metabolite concentrations (grey‐scaled bar graphs), transcript levels (blue for increase, red for decrease) and enzyme activities (green bar graphs) of important enzymes (purple). Bar graphs show data for plants grown in control conditions (left), K‐deficiency for 14 days (centre) and K re‐supply for 24 h (right). Transcript changes in response to K‐deficiency and re‐supply are shown above and below the enzymes respectively. Individual boxes represent individual genes encoding different enzyme isoforms. For details see (Armengaud et al., ).

Figure 4.

Model of how K affects primary metabolism in A. thaliana. Red colour indicates a decrease, blue colour an increase. Low K concentrations in the cytoplasm of root cells inhibit pyruvate kinase thus limiting the glycolytic flux of carbon leading to a build‐up of hexose sugars in roots (sink) with knock‐on affects on shoot hexose levels leading to feedback inhibition of photosynthesis. Root nitrogen metabolism adjusts to a low‐carbon situation by reducing nitrate uptake (down‐regulation of nitrate uptake transporters, NRT) and assimilation (down‐regulation of , NR), and by increasing biosynthesis of (AA) with high N/C ratio. Protein production is maintained at the cost of carbon supply from organic acids, particularly malate, which is used to supplement the TCA cycle through increased activity of malic enzyme. Based on the results of (Armengaud et al., ).

Figure 5.

Root K acquisition in roots. Athak5 is the only system mediating K uptake at external concentrations below 10 μM, probably by K+–H+ symport. At higher concentrations, K uptake takes place also through the akt1 channel and between 10 and 200 μM both systems Athak5 and akt1 contribute to K acquisition. At external concentrations higher than 500 μM, akt1 is the only system mediating K uptake. Athak5 mediates the NH4+‐sensitive component of K uptake and Atakt1 the Ba2+‐sensitive one. In the absence of Athak5 and Atakt1, unknown systems (?) mediate K uptake that is sufficient for plant growth at K concentrations higher than 1 mM.



Alcazar R, Altabella T, Marco F et al. (2010) Polyamines: molecules with regulatory functions in plant abiotic stress tolerance. Planta 231: 1237–1249.

Alemán F, Nieves‐Cordones M and Martinez Rubio F (2009) Differential regulation of the HAK5 genes encoding the high‐affinity K+ transporters of Thellungiella halophila and Arabidopsis thaliana. Environmental and Experimental Botany 65: 263–269.

Alemán F, Nieves‐Cordones M, Martínez V and Rubio F (2011) Root K+ acquisition in plants: the Arabidopsis thaliana model. Plant and Cell Physiology 52: 1603–1612.

Amtmann A and Armengaud P (2009) Effects of N, P, K and S on metabolism: new knowledge gained from multi‐level analysis. Current Opinion in Plant Biology 12: 275–283.

Amtmann A and Blatt MR (2009) Regulation of macronutrient transport. New Phytologist 181: 35–52.

Amtmann A and Leigh RA (2009) Ion Homeostasis. In: Pareek A, Sopory SK, Bohnert HJ and Govindjee   (eds) Abiotic Stress Adaptations in Plant, pp. 245–262. Dordrecht, The Netherlands: Springer.

Amtmann A, Troufflard S and Armengaud P (2008) The effect of potassium nutrition on pest and disease resistance in plants. Physiologia Plantarum 133: 682–691.

Armengaud P, Breitling R and Amtmann A (2004) The potassium‐dependent transcriptome of Arabidopsis reveals a prominent role of jasmonic acid in nutrient signaling. Plant Physiology 136: 2556–2576.

Armengaud P, Sulpice R, Miller AJ et al. (2009) Multilevel analysis of primary metabolism provides new insights into the role of potassium nutrition for glycolysis and nitrogen assimilation in Arabidopsis roots. Plant Physiology 150: 772–785.

Baker DA and Weatherley PE (1969) Water and solute transport by exuding root systems of Ricinus communis. Journal of Experimental Botany 20: 485–496.

Bouchereau A, Aziz A, Larher F and Martin‐Tanguy J (1999) Polyamines and environmental challenges: recent development. Plant Science 140: 103–125.

Dreyer I and Blatt MR (2009) What makes a gate? The ins and outs of Kv‐like K(+) channels in plants. Trends in Plant Science 14: 383–390.

Epstein E, Rains DW and Elzam OE (1963) Resolution of dual mechanisms of potassium absorption by barley roots. Proceedings of the National Academy of Sciences of the USA 49: 684–692.

Evans HJ and Sorger GJ (1966) Role of mineral elements with emphasis on the univalent cations. Annual Review of Plant Physiology 17: 47–76.

Hirai MY, Klein M, Fujikawa Y et al. (2005) Elucidation of gene‐to‐gene and metabolite‐to‐gene networks in Arabidopsis by integration of metabolomics and transcriptomics. Journal of Biological Chemistry 280: 25590–25595.

Kanai S, Ohkura K, Adu‐Gyamfi J et al. (2007) Depression of sink activity precedes the inhibition of biomass production in tomato plants subjected to potassium deficiency stress. Journal of Experimental Botany 58: 2917–2928.

Li R, Volenec JJ, Joern BC and Cunningham SM (1997) Potassium and nitrogen effects on carbohydrate and protein metabolism in Alfalfa roots. Journal of Plant Nutrition 20: 511–529.

Maathuis FJM and Amtmann A (1999) K+ nutrition and Na+ toxicity: the basis of cellular K+/Na+ ratios. Annals of Botany 84: 123–133.

Maathuis FJM, Filatov V, Herzyk P et al. (2003) Transcriptome analysis of root transporters reveals participation of multiple gene families in the response to cation stress. Plant Journal 35: 675–692.

Maathuis FJM and Sanders D (1996) Mechanisms of potassium absorption by higher plant roots. Physiologia Plantarum 96: 158–168.

Marschner H, Kirkby EA and Cakmak I (1996) Effect of mineral nutritional status on shoot‐root partitioning of photoassimilates and cycling of mineral nutrients. Journal of Experimental Botany 47: 1255–1263.

Marschner H (1995) Mineral Nutrition Of Higher Plants, 2nd Edn. London: Academic Press.

Mengel K and Simic R (1973) Effect of potassium supply on acropetal transport of water, inorganic ions and amino‐acids in young decapitated sunflower plants (Helianthus annus). Physiologia Plantarum 28: 232–236.

Nieves‐Cordones M, Aleman F, Martinez V and Rubio F (2010) The Arabidopsis thaliana HAK5 K+ transporter is required for plant growth and K+ acquisition from low K+ solutions under saline conditions. Molecular Plant 3: 326–333.

Nieves‐Cordones M, Martinez‐Cordero MA, Martinez V and Rubio F (2007) An NH4+‐sensitive component dominateshigh‐affinity K+ uptake in tomato plants. Plant Science 172: 273–280.

Nitsos RE and Evans HJ (1969) Effects of univalent cations on the activity of particulate starch synthetase. Plant Physiology 44: 1260–1266.

Peoples TR and Koch DW (1979) Role of potassium in carbon dioxide assimilation in Medicago sativa L. Plant Physiology 63: 878–881.

Ramirez‐Silva L and Oria‐Hernandez J (2003) Selectivity of pyruvate kinase for Na+ and K+ in water/dimethylsulfoxide mixtures. European Journal of Biochemistry 270: 2377–2385.

Rodríguez‐Navarro A and Rubio F (2006) High‐affinity potassium and sodium transport systems in plants. Journal of Experimental Botany 57: 1149–1160.

Rufty TW, Jackson WA and Raper CD (1981) Nitrate reduction in roots as affected by the presence of potassium and by flux of nitrate through the roots. Plant Physiology 68: 605–609.

Sentenac H, Bonneaud N, Minet M et al. (1992) Cloning and expression in yeast of a plant potassium ion transport system. Science 256: 663–665.

Shabala S and Cuin TA (2008) Potassium transport and plant salt tolerance. Physiologia Plantarum 133: 651–669.

Shabala S, Cuin TA and Pottosin I (2007) Polyamines prevent NaCl‐induced K+ efflux from pea mesophyll by blocking non‐selective cation channels. FEBS Letters 581: 1993–1999.

Shin R, Berg RH and Schachtman DP (2005) Reactive oxygen species and root hairs in Arabidopsis root response to nitrogen, phosphorus and potassium deficiency. Plant Cell Physiology 46: 1350–1357.

Smith CR, Knowles VL and Plaxton WC (2000) Purification and characterization of cytosolic pyruvate kinase from Brassica napus (rapeseed) suspension cell cultures: implications for the integration of glycolysis with nitrogen assimilation. European Journal of Biochemistry 267: 4477–4485.

Subbarao GV, Wheeler RM, Stutte GW and Levine LH (2000) Low potassium enhances sodium uptake in red‐beet under moderate saline conditions. Journal of Plant Nutrition 23: 1449–1470.

Thrower SL and Thrower LB (1976) Translocation of labelled assimilate in potassium deficient plants. New Phytologist 77: 541–545.

Trontin C, Tisne S, Bach L and Loudet O (2011) What does Arabidopsis natural variation teach us (and does not teach us) about adaptation in plants? Current Opinion in Plant Biology 14: 225–231.

Véry AA and Sentenac H (2003) Molecular mechanisms and regulation of K+ transport in higher plants. Annual Review of Plant Physiology 54: 575–603.

Walker DJ, Leigh RA and Miller AJ (1996) Potassium homeostasis in vacuolate plant cells. Proceedings ofthe National Academy of Sciences of the USA 93: 10510–10514.

Walter AJ and Difonzo CD (2007) Soil potassium deficiency affects soybean phloem nitrogen and soybean aphid populations. Environmental Entomology 36: 26–33.

White PJ and Brown PH (2010) Plant nutrition for sustainable development and global health. Annals of Botany 105: 1073–1080.

Whiteman SA, Nuhse TS, Ashford DA, Sanders D and Maathuis FJM (2008) A proteomic and phosphoproteomic analysis of Oryza sativa plasma membrane and vacuolar membrane. Plant Journal 56: 146–156.

Wyn Jones RJ and Pollard A (1983) Proteins, enzymes and inorganic ions. In: Lauchli A and Pirson A (eds) Encyclopedia of Plant Physiology, pp. 528–562. Berlin: Springer.

Yamada S, Osaki M, Shinano T et al. (2002) Effect of potassium nutrition on current photosynthesized carbon distribution to carbon and nitrogen compounds among rice, soybean and sunflower. Journal of Plant Nutrition 25: 1957–1973.

Yamashita T and Fujiwara A (1967) Metabolism of acetate‐1‐14C in excised leaves from potassium deficient rice seedlings. Plant Cell Physiology 8: 557–565.

Yang XE, Liu JX, Wang WM, Ye ZQ and Luo AC (2004) Potassium internal use efficiency relative to growth vigor, potassium distribution, and carbohydrate allocation in rice genotypes. Journal of Plant Nutrition 27: 837–852.

Further Reading

Nieves‐Cordones M, Alemán F, Fon M, Martínez V and Rubio F (2010) K+ nutrition, uptake and its role in environmental stress in plants. In: Ahmad P and Prasad MNV (eds) Environmental Adaptations and Stress tolerance of Plants in the Era of Climate Change. New York: Springer.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Amtmann, Anna, and Rubio, Francisco(May 2012) Potassium in Plants. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0023737]