Repression of Nitrate Uptake by Replacement of Asp105 by Asparagine in AtNRT3.1 in Arabidopsis thaliana L.

Kawachi, Tahei; Sunaga, Yoshihito; Ebato, Munehiro; Hatanaka, Takeshi; Harada, Hiroyuki

doi:10.1093/pcp/pcl010

Cited by 22 publications

(24 citation statements)

References 15 publications

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“…However, the region of NAR2 involving in interaction with NRT2 has not been clarified although the functional importance of aspartate residue in the central loop of NAR2 for HATS activity was suggested (Kawachi et al 2006). In this study, affinity-column binding analysis clearly showed that a direct protein-protein interaction occurred between the HvNRT2.1 C-terminal and the HvNAR2.3 central region.…”

mentioning

confidence: 73%

“…Indeed, there are several predicted phosphorylation sites (serine and threonine residues) in the C-terminus of HvNRT2.1 (Figure 1). On the other hand, in the rnc1 mutant of Arabidopsis, it has been shown that a conserved aspartate residue located in the central region of NAR2 protein is important for exhibiting HATS activity (Figure 1, Kawachi et al 2006). Therefore, the possibility of protein-protein interaction between HvNRT2 C-term and HvNAR2 cent was studied by affinity-column binding analysis.…”

Section: Immunological Detection Of Hvnrt2 and Hvnar2 Proteins In Memmentioning

confidence: 99%

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Two-component high-affinity nitrate transport system in barley: Membrane localization, protein expression in roots and a direct protein-protein interaction

Ishikawa

Ito

Sato

et al. 2009

Plant Biotechnology

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Nitrate is one of the major sources of nitrogen for higher plants and is taken up from the soil by active transporters coupled with H ϩ across the plasma membrane (PM) of root cells. Nitrate uptake systems have been classified into two groups: low-affinity transport systems (LATS) and high-affinity transport systems (HATS). The LATS contribute to nitrate uptake at high nitrate concentrations above 1 mM whereas the HATS operate at micromolar concentrations of external nitrate and display MichaelisMenten kinetics saturating at 0.2-0.5 mM nitrate. The HATS are further divided into two categories: constitutive HATS (cHATS) and inducible HATS (iHATS), which are significantly affected by the supply of external nitrate. Many studies of the molecular basis of nitrate uptake reveal the existence of two gene families, namely the NRT1 and NRT2 families, which potentially encode for LATS and HATS respectively. NRT2 genes are identified in a variety of organisms including fungi, certain yeasts, green algae, and higher plants ( Unkles et al. 1991;Quesada et al. 1994;Trueman et al. 1996;Pérez et al. 1997;Quesada et al. 1997;Amarasinghe et al. 1998;Zhuo et al., 1999;Araki and Hasegawa 2006;Tsujimoto et al. 2007). In most species, NRT2 genes are members of a multigene family: for example, seven Arabidopsis genes (AtNRT2.1-AtNRT2.7) and four rice genes (OsNRT2.1-OsNRT2.4) have been found in their genomes (Orsel et al. 2002; Araki and Hasegawa 2007), and at least four NRT2 genes (HvNRT2.1-HvNRT2.4) exist in barley (Vidmar 2000a). Amino acid sequences deduced from these genes indicate that the NRT2 proteins are typically 480-510 amino acids in length and predicted to be integral to membranes with 12 transmembrane helices (Forde 2000).It has been well documented that iHATS activity is strongly induced by nitrate supply, and is down-regulated by the accumulation of nitrate assimilation products, especially ammonium and glutamine (Crawford and Glass 1998). In several plant species, it has been shown that a particular member of the NRT2 gene family (e.g., NpNRT2.1 for Nicotiana plumbaginifolia, AtNRT2.1 for Arabidopsis, HvNRT2.1 for barley) contribute to iHATS, because those transcript levels are highly correlated with changes in iHATS activity in such species (Krapp et al. 1998;Lejay et al. 1999;Zhuo et al. 1999;Vidmar et al. 2000a Abstract A high affinity transport system (HATS) for nitrate in plants is operated by a two-component NRT2/NAR2 transport system. However, the regulation and localization of NRT2 and NAR2 at protein level are largely unknown and especially so in crop plant species. In this study with barley (Hordeum vulgare), membrane localization, protein expression in the roots, and a direct protein-protein interaction of HvNRT2 and HvNAR2 proteins were investigated. Immunochemical analysis showed that both HvNRT2 and HvNAR2 proteins were co-localized in the plasma membrane of the roots. Expression of HvNRT2 and HvNAR2 proteins was more strongly induced by treatment with higher concentrations of external nitrate, while H...

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mentioning

confidence: 73%

Section: Immunological Detection Of Hvnrt2 and Hvnar2 Proteins In Memmentioning

confidence: 99%

Two-component high-affinity nitrate transport system in barley: Membrane localization, protein expression in roots and a direct protein-protein interaction

Ishikawa

Ito

Sato

et al. 2009

Plant Biotechnology

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“…This process was repeated once more using additional SNP markers SNP21.4 and SNP21.5, resulting in the mapping of the resistance locus to a 130-kb region. SNP analysis was performed as described previously (Kawachi et al, 2006). Primer information for the SSLP markers was obtained from the TAIR database (http://www.Arabidopsis.org/).…”

Section: Genetic Analysismentioning

confidence: 99%

Lectin-Mediated Resistance Impairs Plant Virus Infection at the Cellular Level

et al. 2012

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Plants possess a multilayered defense response, known as plant innate immunity, to infection by a wide variety of pathogens. Lectins, sugar binding proteins, play essential roles in the innate immunity of animal cells, but the role of lectins in plant defense is not clear. This study analyzed the resistance of certain Arabidopsis thaliana ecotypes to a potexvirus, plantago asiatica mosaic virus (PlAMV). Map-based positional cloning revealed that the lectin gene JACALIN-TYPE LECTIN REQUIRED FOR POTEXVIRUS RESISTANCE1 (JAX1) is responsible for the resistance. JAX1-mediated resistance did not show the properties of conventional resistance (R) protein-mediated resistance and was independent of plant defense hormone signaling. Heterologous expression of JAX1 in Nicotiana benthamiana showed that JAX1 interferes with infection by other tested potexviruses but not with plant viruses from different genera, indicating the broad but specific resistance to potexviruses conferred by JAX1. In contrast with the lectin gene RESTRICTED TEV MOVEMENT1, which inhibits the systemic movement of potyviruses, which are distantly related to potexviruses, JAX1 impairs the accumulation of PlAMV RNA at the cellular level. The existence of lectin genes that show a variety of levels of virus resistance, their targets, and their properties, which are distinct from those of known R genes, suggests the generality of lectin-mediated resistance in plant innate immunity.

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“…The shaded letters indicate the amino acid residues conserved in at least four of the five sequences. The triangle indicates the aspartate residue shown to be essential for nitrate transport in A. thaliana (Kawachi et al 2006). Regulation of nitrate transport genes 487 (Trueman et al 1996), was conserved in the five PpNRT2 proteins, although the methionine residue was replaced with a leucine residue in the moss proteins.…”

Section: Characteristics Of the Deduced Ppnrt2 Proteinsmentioning

confidence: 99%

Distinct Roles of Nitrate and Nitrite in Regulation of Expression of the Nitrate Transport Genes in the Moss Physcomitrella patens

Tsujimoto

Yamazaki

Maeda

et al. 2007

Plant and Cell Physiology

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Five NRT2 genes and three Nar2 genes, encoding putative high-affinity nitrate transporters, and the respective cDNAs were identified and characterized in Physcomitrella patens. The deduced moss NRT2 and NAR2 proteins were more similar to the corresponding proteins of higher plants than to those of the green alga Chlamydomonas reinhardtii. Expression of all the genes was inhibited by ammonium added to the medium. The regulation by ammonium was abolished by an inhibitor of glutamine synthetase, but the effect of this inhibitor was counteracted by an inhibitor of glutamate synthase. Negative correlation was observed between the glutamine content of protonemata and the transcript levels of PpNRT2 and PpNar2. These results indicated that glutamine is the signal for repression of the genes. All the genes except PpNRT2;5 showed transient expression stimulated by nitrate but not by nitrite, peaking at 2-4 h after the medium was deprived of ammonium. When the glutamine synthetase inhibitor was used to inhibit assimilation of the ammonium generated intracellularly from nitrate or nitrite, the second phase of activation of genes became manifest at $8 h after the medium was deprived of ammonium. Surprisingly, both nitrate and nitrite stimulated gene expression at this stage. PpNRT2;5 was distinct from the other genes in that its expression is sharply induced by nitrite, is strictly dependent on nitrite or nitrate, and is much less susceptible to the feedback regulation, retaining a constant level in nitratecontaining medium. These results indicated that P. patens has multiple mechanisms for sensing nitrate and nitrite.

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Repression of Nitrate Uptake by Replacement of Asp105 by Asparagine in AtNRT3.1 in Arabidopsis thaliana L.

Cited by 22 publications

References 15 publications

Two-component high-affinity nitrate transport system in barley: Membrane localization, protein expression in roots and a direct protein-protein interaction

Two-component high-affinity nitrate transport system in barley: Membrane localization, protein expression in roots and a direct protein-protein interaction

Lectin-Mediated Resistance Impairs Plant Virus Infection at the Cellular Level

Distinct Roles of Nitrate and Nitrite in Regulation of Expression of the Nitrate Transport Genes in the Moss Physcomitrella patens

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