Original scientific paper

Genetic analysis of a nodA-nodD region of autochthonous strains of Rhizobium leguminosarum biovar viciae that showed effective nodulation of host plants

JELENA ŽAFRAN-NOVAK ; GMO Quantification and Risk Assessment Unit, Croatian National Institute for Public, Health, Rockefellerova 7, 10000 Zagreb, Croatia
SULEJMAN REDŽEPOVIĆ ; Department of Microbiology, Faculty of Agriculture, Svetošimunska 25, 10000 Zagreb, Croatia
HELENA ĆETKOVIĆ ; Division of Molecular Biology, Ruđe Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia

Abstract

Two autochthonous strains of R. leguminosarum bv. viciae, designated 201ZG and 301ZG, were isolated from large and numerous root nodules of peas and vetches where these symbiotic bacteria fix nitrogen into ammonia. In preliminary biological experiments, both local isolates showed a better
nodulation efficacy than control referent strain R. leguminosarum bv.
viciae 248. The most important nodulation genes nodA and nodD, and the bidirectional promoter region between them, were cloned, sequenced and compared with the referent strain.
Many changes in the primary structure of nod genes and the major promoter region were detected in both strains. Amino acid sequences of NodA and NodD proteins have changed up to 6.6% and 3.6%, respectively. The changes were conservative, however, and located at positions where variations had already been detected in both proteins. The nod boxes, which are essential to the function of the promoter region, were well conserved in both
strains. The results of this study provide an insight into the primary structure of nodA-nodD region in both autochthonous strains and in the possible association with the better nodulation and nitrogen fixation which showed biological experiment in greenhouse.

Keywords

nodA and nodD genes; nodA promoter; nitrogen fixation; nodulation

Hrčak ID:

63696

URI

https://hrcak.srce.hr/63696

Publication date:

31.12.2010.

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