Journal Article

The Arabidopsis Nitrate Transporter NRT2.4 Plays a Double Role in Roots and Shoots of Nitrogen-Starved Plants

Boutet-Mercey, Stéphanie, Lezhneva, Lina, Daniel-Vedele, Françoise, Sakakibara, Hitoshi, Feria-Bourrellier, Ana-Belen, Bréhaut, Virginie, Krapp, Anne, Kiba, Takatoshi, Miller, Anthony, Lafouge, Florence, Orsel, Mathilde

2012

Overview

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 ß-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 NRT2A 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 nrX2A 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.

• Publisher: American Society of Plant Biologists,American Society of Plant Biologists (ASPB)
• Subject: Anion Transport Proteins / Anion Transport Proteins - genetics / Anion Transport Proteins - metabolism / Arabidopsis / Arabidopsis - genetics / Arabidopsis - metabolism / Arabidopsis Proteins / Arabidopsis Proteins - genetics / Arabidopsis Proteins - metabolism / Arabidopsis thaliana / beta-glucuronidase / biomass production / Cell membranes / deficiency / Epidermis / epidermis (plant) / Fluorescence / gene expression / Genetics / green fluorescent protein / Life Sciences / metabolism / Microscopy, Confocal / Nitrate Transporters / Nitrates / Nitrogen / Nitrogen - deficiency / Nitrogen - metabolism / nutrient deficiencies / nutrient uptake / Oocytes / Phloem / Plant cells / Plant roots / Plants / Plants genetics / plasma membrane / reporter genes / Roots / Seedlings / Shoots / Starvation / transporters / Xenopus laevis