Regulation of a putative high-affinity nitrate transporter (Nrt2;1At) in roots of Arabidopsis thaliana

Plant J. 1999 Mar;17(5):563-8. doi: 10.1046/j.1365-313x.1999.00396.x.


Putative high-affinity nitrate (NO3-) transporter genes, designated Nrt2;1At and Nrt2;2At, were isolated from Arabidopsis thaliana by RT-PCR using degenerate primers. The genes shared 86% and 89% identity at the amino acid and nucleotide levels, respectively, while their proteins shared 30-73% identities with other eukaryotic high-affinity NO3- transporters. Both genes were induced by NO3-, but Nrt2;1At gene expression was not apparent in 2- and 5-day-old plants. By 10 days, and thereafter, Nrt2;1At gene expression in roots was substantially higher than for the Nrt2;2At gene. Root Nrt2;1At expression levels were strongly correlated with inducible high-affinity 13NO3- influx into intact roots under several treatment conditions. The use of inhibitors of N assimilation indicated that downregulation of Nrt2;1At expression was mediated by NH4+, gln and other amino acids.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anion Transport Proteins*
  • Arabidopsis / genetics*
  • Arabidopsis Proteins*
  • Biological Transport, Active
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Gene Expression Regulation, Plant*
  • Molecular Sequence Data
  • Nitrates / metabolism*
  • Plant Proteins*
  • Plant Roots / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction


  • Anion Transport Proteins
  • Arabidopsis Proteins
  • Carrier Proteins
  • NRT2 protein, Arabidopsis
  • Nitrates
  • Plant Proteins
  • nitrate transporters

Associated data

  • GENBANK/AF019748
  • GENBANK/AF019749