Potassium (K+) gradients serve as a mobile energy source in plant vascular tissues

Proc Natl Acad Sci U S A. 2011 Jan 11;108(2):864-9. doi: 10.1073/pnas.1009777108. Epub 2010 Dec 27.


The essential mineral nutrient potassium (K(+)) is the most important inorganic cation for plants and is recognized as a limiting factor for crop yield and quality. Nonetheless, it is only partially understood how K(+) contributes to plant productivity. K(+) is used as a major active solute to maintain turgor and to drive irreversible and reversible changes in cell volume. K(+) also plays an important role in numerous metabolic processes, for example, by serving as an essential cofactor of enzymes. Here, we provide evidence for an additional, previously unrecognized role of K(+) in plant growth. By combining diverse experimental approaches with computational cell simulation, we show that K(+) circulating in the phloem serves as a decentralized energy storage that can be used to overcome local energy limitations. Posttranslational modification of the phloem-expressed Arabidopsis K(+) channel AKT2 taps this "potassium battery," which then efficiently assists the plasma membrane H(+)-ATPase in energizing the transmembrane phloem (re)loading processes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / genetics
  • Computational Biology / methods
  • Gene Expression Regulation, Plant*
  • Genes, Plant
  • Genome, Plant
  • Models, Biological
  • Models, Genetic
  • Models, Theoretical
  • Mutation
  • Oxygen / chemistry
  • Phenotype
  • Plant Physiological Phenomena
  • Potassium / chemistry*
  • Potassium Channels / genetics
  • Protein Processing, Post-Translational


  • AKT2 protein, Arabidopsis
  • Arabidopsis Proteins
  • Potassium Channels
  • Potassium
  • Oxygen