Identification of a 150 bp cis-acting element of the AtNRT2.1 promoter involved in the regulation of gene expression by the N and C status of the plant

Plant Cell Environ. 2007 Nov;30(11):1366-80. doi: 10.1111/j.1365-3040.2007.01712.x.


The Arabidopsis thaliana AtNRT2.1 gene, which encodes a NO(3)(-) transporter involved in high-affinity uptake by the roots, is a molecular target of several mechanisms responsible for the regulation of root NO(3)(-) acquisition by the N status of the plant. All levels of AtNRT2.1 expression (promoter activity, transcript level, protein accumulation, transport activity) are coordinately up-regulated in the presence of NO(3)(-), and repressed by downstream N metabolites. Transgenic plants expressing the GUS reporter gene under the control of upstream sequences of AtNRT2.1 have been studied to identify elements targeted by these two regulatory mechanisms. A 150 bp sequence located upstream of the TATA box that is required for both stimulation by NO(3)(-) and repression by N metabolites of the promoter has been identified. This sequence is able to confer these two regulations to a minimal promoter. Split-root experiments indicate that the stimulation of the chimaeric promoter by NO(3)(-) occurs only at the local level, whereas its repression by N metabolites is mediated by a systemic signal spread to the whole plant. The activity of the cis-acting 150 bp element is also regulated by sucrose supply to the roots, suggesting a possible interaction between N and C signalling within this short region. Accordingly, multiple motifs potentially involved in regulations by N and/or C status are identified within this sequence by bioinformatic approaches. This is the first report of such a cis-acting element in higher plants.

MeSH terms

  • Anion Transport Proteins / genetics*
  • Arabidopsis / genetics*
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / genetics*
  • Carbohydrates
  • Carbon / metabolism*
  • Computational Biology
  • Gene Expression Regulation, Plant / genetics*
  • Nitrogen / metabolism*
  • Plant Roots / metabolism
  • Plant Shoots / metabolism
  • Promoter Regions, Genetic / genetics*
  • Transcription, Genetic


  • Anion Transport Proteins
  • Arabidopsis Proteins
  • AtNRT2.1 protein, Arabidopsis
  • Carbohydrates
  • Carbon
  • Nitrogen