Ion transport properties of grape root lipids were measured as liquid-membrane permeability. Phosphatidylcholine exchanged chloride very slowly against carbonate and bicarbonate but more rapidly against nitrate, phosphate, and sulfate. Exchange of chloride against nitrate was rather low for the phosphatidylcholine and phosphatidylethanolamine lipid fractions; monogalactose diglyceride was by fa...

Lateral root initiation is strongly repressed in Arabidopsis by the combination of high external sucrose and low external nitrate. A previously isolated mutant, lin1, can overcome this repression. Here, we show that lin1 carries a missense mutation in the NRT2.1 gene. Several allelic mutants, including one in which the NRT2.1 gene is completely deleted, show similar phenotypes to lin1 and fail ...

In papers by Wang et al. (1998), Liu et al. (1999), and Liu and Tsay (2003), it was proposed that Arabidopsis thaliana Nitrate Transporter1.1 (AtNRT1.1; CHL1) encodes a dual-affinity nitrate transporter that “plays a major role in high-affinity nitrate uptake.” Here, we evaluate this concept by reexamining the uptake kinetics of Arabidopsis (Arabidopsis thaliana) mutant lines defective in NRT1....

In papers by Wang et al. (1998), Liu et al. (1999), and Liu and Tsay (2003), it was proposed that Arabidopsis thaliana Nitrate Transporter1.1 (AtNRT1.1; CHL1) encodes a dual-affinity nitrate transporter that “plays a major role in high-affinity nitrate uptake.” Here, we evaluate this concept by reexamining the uptake kinetics of Arabidopsis (Arabidopsis thaliana) mutant lines defective in NRT1....

Dipeptide (Leu-Leu) and nitrate transport activities of 26 Arabidopsis NPF (NRT1/PTR Family) proteins were screened in Saccharomyces cerevisiae and Xenopus laevis oocytes, respectively. Dipeptide transport activity has been confirmed for 2 already known dipeptide transporters (AtNPF8.1 and AtNPF8.3) but none of the other tested NPFs displays dipeptide transport. The nitrate transport screen res...

Several quantitative trait locus analyses have suggested that grain yield and nitrogen use efficiency are well correlated with nitrate storage capacity and efficient remobilization. This study of the Arabidopsis thaliana nitrate transporter NRT1.7 provides new insights into nitrate remobilization. Immunoblots, quantitative RT-PCR, beta-glucuronidase reporter analysis, and immunolocalization ind...

Poaceae plants release phytosiderophores into the rhizosphere in order to chelate iron (Fe), which often exists in insoluble forms especially under high pH conditions. The impact of phytosiderophore treatment at the physiological and molecular levels in vivo remains largely elusive, although the biosynthesis of phytosiderophores and the transport of phytosiderophore-metal complexes have been we...

In Arabidopsis the plasmamembrane nitrate transceptor (transporter/receptor) NRT1.1 governs many physiological and developmental responses to nitrate. Alongside facilitating nitrate uptake, NRT1.1 regulates the expression levels of many nitrate assimilation pathway genes, modulates root system architecture, relieves seed dormancy and protects plants from ammonium toxicity. Here, we assess the f...