Type-B response regulators ARR1 and ARR12 regulate expression of AtHKT1;1 and accumulation of sodium in Arabidopsis shoots

Michael G. Mason, Deepa Jha, David E. Salt, Mark Tester, Kristine Hill, Joseph J. Kieber, G. Eric Schaller

Research output: Contribution to journalArticle

76 Citations (Scopus)

Abstract

P>Soil salinity affects a large proportion of the land worldwide, forcing plants to evolve a number of mechanisms to cope with salt stress. Cytokinin plays a role in the plant response to salt stress, but little is known about the mechanism by which cytokinin controls this process. We used a molecular genetics approach to examine the influence of cytokinin on sodium accumulation and salt sensitivity in Arabidopsis thaliana. Cytokinin application was found to increase sodium accumulation in the shoots of Arabidopsis, but had no significant affect on the sodium content in the roots. Consistent with this, altered sodium accumulation phenotypes were observed in mutants of each gene class of the cytokinin signal transduction pathway, including receptors, phospho-transfer proteins, and type-A and type-B response regulators. Expression of the gene encoding Arabidopsis high-affinity K+ transporter 1;1 (AtHKT1;1), a gene responsible for removing sodium ions from the root xylem, was repressed by cytokinin treatment, but showed significantly elevated expression in the cytokinin response double mutant arr1-3 arr12-1. Our data suggest that cytokinin, acting through the transcription factors ARR1 and ARR12, regulates sodium accumulation in the shoots by controlling the expression of AtHKT1;1 in the roots.

Original languageEnglish
Pages (from-to)753-763
Number of pages11
JournalThe Plant Journal
Volume64
Issue number5
Early online date26 Oct 2010
DOIs
Publication statusPublished - Dec 2010

Keywords

  • cytokinin
  • sodium accumulation
  • AtHKT1
  • 1
  • ion transport
  • salinity
  • response regulator
  • cytokinin signal-transduction
  • solanum-lycopersicon L.
  • salt tolerance
  • abscisic-acid
  • salinity tolerance
  • functional-analysis
  • hormonal changes
  • leaf senescence
  • NA+ transport
  • wheat plants

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