Cloning and expression of a gene encoding a root specific nitrate reductase in bean ( Phaseolus vulgaris )
1991; Wiley; Volume: 82; Issue: 2 Linguagem: Inglês
10.1111/j.1399-3054.1991.tb00081.x
ISSN1399-3054
AutoresTine Hoff, Bjarne M. Stummann, Knud W. Henningsen,
Tópico(s)Plant Micronutrient Interactions and Effects
ResumoA structural gene encoding nitrate reductase (NR) in the legume Phaseolus vulgaris cv. Saxonia has been cloned and sequenced. The NR gene encodes a protein of 881 amino acids with a MW of 99.2 kDa. The coding sequence is interrupted by three introns, which are located in the molybdopterin cofactor binding domain. In the flanking regions the signals of a functional eukaryotic gene are present. The gene is the smallest NR gene so far identified in higher plants. Comparison to other NRs shows homology ranging from 65 to 74% at the amino acid level. The similarity is highest for the three functional domains, and lowest in the N‐terminal end of the protein. mRNA studies demonstrate that the gene is nitrate inducible and expressed exclusively in the roots of bean. Southern blot analysis indicates the presence of a second NR gene in bean. This gene may encode a NR enzyme expressed in leaves.
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