GmAKT1 is involved in K+ uptake and Na+/K+ homeostasis in Arabidopsis and soybean plants

Plant Sci. 2021 Mar;304:110736. doi: 10.1016/j.plantsci.2020.110736. Epub 2020 Nov 4.

Abstract

Plant roots absorb K+ from soil via K+ channels and transporters, which are important for stress responses. In this research, GmAKT1, an AKT1-type K+ channel, was isolated and characterized. The expression of GmAKT1 was induced by K+-starvation and salinity stresses, and it was preferentially expressed in the soybean roots. And GmAKT1 was located in the plasma membrane. As an inward K+ channel, GmAKT1 participated in K+ uptake, as well as rescued the low-K+-sensitive phenotype of the yeast mutant and Arabidopsis akt1 mutant. Overexpression of GmAKT1 significantly improved the growth of plants and increased K+ concentration, leading to lower Na+/K+ ratios in transgenic Arabidopsis and chimeric soybean plants with transgenic hairy roots. In addition, GmAKT1 overexpression resulted in significant upregulation of these ion uptake-related genes, including GmSKOR, GmsSOS1, GmHKT1, and GmNHX1. Our findings suggested that GmAKT1 plays an important part in K+ uptake under low-K+ condition, and could maintain Na+/K+ homeostasis under salt stress in Arabidopsis and soybean plants.

Keywords: Glycine max; GmAKT1; K(+)uptake; Na(+)/K(+)homeostasis; Salt tolerance.

MeSH terms

  • Arabidopsis
  • Gene Expression Regulation, Plant
  • Homeostasis
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Plant Proteins / physiology
  • Plant Roots / metabolism
  • Plants, Genetically Modified
  • Polymerase Chain Reaction
  • Potassium / metabolism*
  • Potassium Channels / genetics
  • Potassium Channels / metabolism*
  • Potassium Channels / physiology
  • Salt Stress
  • Sodium / metabolism*
  • Soybeans / genetics
  • Soybeans / metabolism*

Substances

  • Plant Proteins
  • Potassium Channels
  • Sodium
  • Potassium