Overexpression of the rice AKT1 potassium channel affects potassium nutrition and rice drought tolerance

J Exp Bot. 2016 Apr;67(9):2689-98. doi: 10.1093/jxb/erw103. Epub 2016 Mar 11.


Potassium (K(+)) is the most important cationic nutrient for all living organisms and has roles in most aspects of plant physiology. To assess the impact of one of the main K(+) uptake components, the K(+) inward rectifying channel AKT1, we characterized both loss of function and overexpression of OsAKT1 in rice. In many conditions, AKT1 expression correlated with K(+) uptake and tissue K(+) levels. No salinity-related growth phenotype was observed for either loss or gain of function mutants. However, a correlation between AKT1 expression and root Na(+) when the external Na/K ratio was high suggests that there may be a role for AKT1 in Na(+) uptake in such conditions. In contrast to findings with Arabidopsis thaliana, we did not detect any change in growth of AKT1 loss of function mutants in the presence of NH4 (+) Nevertheless, NH4 (+)-dependent inhibition was detected during K(+) uptake assays in loss of function and wild type plants, depending on pre-growth conditions. The most prominent result of OsAKT1 overexpression was a reduction in sensitivity to osmotic/drought stress in transgenic plants: the data suggest that AKT1 overexpression improved rice osmotic and drought stress tolerance by increasing tissue levels of K(+), especially in the root.

Keywords: Drought; Oryza sativa; OsAKT1; ion channel; osmotic stress; rice..

MeSH terms

  • Dehydration
  • Oryza / metabolism
  • Oryza / physiology*
  • Plant Proteins / metabolism*
  • Plant Proteins / physiology
  • Plant Roots / metabolism
  • Plant Shoots / metabolism
  • Plants, Genetically Modified
  • Potassium / metabolism
  • Potassium Channels / metabolism*
  • Potassium Channels / physiology


  • Plant Proteins
  • Potassium Channels
  • Potassium