ISSN:
1399-3054
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
A full-length cDNA encoding for ferredoxin-nitrite reductase (NiR, EC 1.7.7.1), has been isolated from a root cDNA library from the legume Lotus japonicus and characterised. The NiR gene (Nii) is present as a single copy in this plant, and encodes a protein of 582 amino acids. The Lotus NiR protein is synthesised as a precursor with an amino-terminal transit peptide consisting of 25 amino acid residues. Sequence comparisons with leaf NiRs from different plant species and with other related redox proteins identified in the root NiR the same highly conserved residues involved in the cofactor binding than previously reported for leaves. Besides, a putative binding site for ferredoxin was also found in the N-terminal region of the protein. The NiR gene is expressed in roots and leaves, although the level of expression is much higher in roots, in accordance with the fact that L. japonicus assimilates nitrate mainly in roots. NiR mRNA, protein and activity are induced by nitrate in roots and leaves, while ammonium-grown plants only showed basal levels. No oscillations of NiR mRNA, protein and activity were observed during the day/night cycle, neither in roots nor leaves, making an interesting difference with rhythms observed in other plant species.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1034/j.1399-3054.2001.1130206.x
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