Journal Article

Regulation of <i>NRT1</i> and <i>NRT2</i> Gene Families of <i>Arabidopsis thaliana</i>: Responses to Nitrate Provision

Mamoru Okamoto, J. John Vidmar and Anthony D. M. Glass

in Plant and Cell Physiology

Published on behalf of Japanese Society of Plant Physiologists

Volume 44, issue 3, pages 304-317
Published in print March 2003 | ISSN: 0032-0781
Published online March 2003 | e-ISSN: 1471-9053 | DOI:
Regulation of NRT1 and NRT2 Gene Families of Arabidopsis thaliana: Responses to Nitrate Provision

More Like This

Show all results sharing these subjects:

  • Biochemistry
  • Molecular and Cell Biology
  • Plant Sciences and Forestry


Show Summary Details


Four low-affinity (NRT1), and seven high-affinity (NRT2) nitrate transporter gene homologues have been identified in Arabidopsis thaliana. We investigated the transcript abundances of all eleven genes in shoot and root tissues in response to the provision of 1 mM NO3, using relative quantitative RT-PCR. Based upon this criterion, genes were classified as nitrate-inducible, nitrate-repressible, or nitrate-constitutive. AtNRT1.1, 2.1, and 2.2 were strongly induced by NO3, peaking at 3–12 h and subsequently declining. By contrast AtNRT2.4 showed only modest induction both in shoots and roots. Expression of AtNRT2.5, one of the nitrate-repressible genes, was strongly suppressed by nitrate provision in both roots and shoots. The last group, characterized by a constitutive expression pattern, included AtNRT1.2, 1.4, 2.3, 2.6, and 2.7. Correlation coefficients between 13NO3 influx from 100 µM and 5 mM [NO3], suggest that high- and low-affinity transport systems are mediated primarily by AtNRT2.1 and AtNRT1.1, respectively. Functional roles for the other members of these families remain uncertain.

Keywords: Keywords: Arabidopsis thaliana — Gene expression — HATS/LATS — Nitrate transporter — NRT — 13NO3–.; Abbreviations: CK2, casein kinase 2; HATS, high-affinity transporter system; LATS, low-affinity transporter system; MFS, major facilitator superfamily; NNP, nitrate/nitrite porter; NRT, nitrate transporter; PKC, protein kinase C; RT-PCR, reverse transcription-PCR; TMS, trans-membrane-spanners.

Journal Article.  9364 words.  Illustrated.

Subjects: Biochemistry ; Molecular and Cell Biology ; Plant Sciences and Forestry

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.