Repression of nitrate uptake by replacement of Asp105 by asparagine in AtNRT3.1 in Arabidopsis thaliana L.
An Arabidopsis mutant (rnc1) with a mutation at the 313th nucleotide from the translational start site of AtNRT3.1 was isolated. The mutation resulted in the replacement of aspartate by asparagine at the 105th amino acid in a region conserved among higher plants. In the rnc1 mutant, both the nitrate concentrations in plants and the nitrate uptake from the medium were <13% compared with those of the wild type, while AtNRT3.1 mRNA was accumulated similarly and both AtNRT1.1 and AtNRT2.1 mRNA were decreased. These results suggest that the replacement of Asp105 in AtNRT3.1 markedly reduces nitrate uptake and accumulation.
Kawachi
Tahei
T
National Institute of Livestock and Grassland Science, 768, Senbonmatsu, Nasushiobara, Tochigi, 329-2793 Japan. tahei@affrc.go.jp
Sunaga
Yoshihito
Y
Ebato
Munehiro
M
Hatanaka
Tetsuya
T
Harada
Hisatomi
H
D000595:Amino Acid Sequence; D027321:Anion Transport Proteins / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001216:Asparagine / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008969:Molecular Sequence Data; D009154:Mutation; D009566:Nitrates / Q000378:metabolism*; D018517:Plant Roots; D030821:Plants, Genetically Modified
D027321:Anion Transport Proteins; D029681:Arabidopsis Proteins; C510574:NRT3.1 protein, Arabidopsis; D009566:Nitrates; D001216:Asparagine