The Arabidopsis nitrate transporter NRT2.4 plays a double role in roots and shoots of nitrogen-starved plants.

Abstract

Plants have evolved a variety of mechanisms to adapt to N starvation. NITRATE TRANSPORTER2.4 (NRT2.4) is one of seven NRT2 family genes in Arabidopsis thaliana, and NRT2.4 expression is induced under N starvation. Green fluorescent protein and β-glucuronidase reporter analyses revealed that NRT2.4 is a plasma membrane transporter expressed in the epidermis of lateral roots and in or close to the shoot phloem. The spatiotemporal expression pattern of NRT2.4 in roots is complementary with that of the major high-affinity nitrate transporter NTR2.1. Functional analysis in Xenopus laevis oocytes and in planta showed that NRT2.4 is a nitrate transporter functioning in the high-affinity range. In N-starved nrt2.4 mutants, nitrate uptake under low external supply and nitrate content in shoot phloem exudates was decreased. In the absence of NRT2.1 and NRT2.2, loss of function of NRT2.4 (triple mutants) has an impact on biomass production under low nitrate supply. Together, our results demonstrate that NRT2.4 is a nitrate transporter that has a role in both roots and shoots under N starvation.

• Authors: Takatoshi Kiba, Ana-Belen Feria-Bourrellier, Florence Lafouge, Lina Lezhneva, Stéphanie Boutet-Mercey, Mathilde Orsel, Virginie Bréhaut, Anthony Miller, Françoise Daniel-Vedele, Hitoshi Sakakibara, Anne Krapp
• Journal: The Plant cell (Plant Cell) Vol. 24 Issue 1 Pg. 245-58 (Jan 2012) ISSN: 1532-298X [Electronic] England
• PMID: 22227893 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Anion Transport Proteins
• Arabidopsis Proteins
• AtNRT2.1 protein, Arabidopsis
• NRT2.2 protein, Arabidopsis
• Nitrate Transporters
• Nitrogen

Topics

• Anion Transport Proteins (genetics, metabolism)
• Arabidopsis (genetics, metabolism)
• Arabidopsis Proteins (genetics, metabolism)
• Microscopy, Confocal
• Nitrate Transporters
• Nitrogen (deficiency, metabolism)