A purL mutant of Sinorhizobium fredii HH103 is symbiotically defective and altered in its lipopolysaccharide

• Published in: Microbiology (Society for General Microbiology) Vol. 149; no. 7; pp. 1807 - 1818
• Main Authors: Buendia-Claveria, Ana M, Moussaid, Ahmed, Ollero, F. Javier, Vinardell, Jose M, Torres, Antonio, Moreno, Javier, Gil-Serrano, Antonio M, Rodriguez-Carvajal, Miguel A, Tejero-Mateo, Pilar, Peart, Jan L, Brewin, Nicholas J, Ruiz-Sainz, Jose E
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01-07-2003; Society for General Microbiology
• Subjects: AICA-riboside; Animals; Antibodies, Bacterial; Antibodies, Monoclonal; Bacteriology; Base Sequence; Biological and medical sciences; DNA, Bacterial - genetics; Fundamental and applied biological sciences. Psychology; Genes, Bacterial; Glycine max; Glycine max - microbiology; Glycyrrhiza uralensis; Lipopolysaccharides - chemistry; Lipopolysaccharides - immunology; Lipopolysaccharides - metabolism; Microbiology; Molecular Sequence Data; Morphology, structure, chemical composition; Mutation; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Phenotype; purL gene; Rats; Sinorhizobium - genetics; Sinorhizobium - growth & development; Sinorhizobium - metabolism; Sinorhizobium fredii; Symbiosis - genetics; Characterization; Symbiosis; Lipopolysaccharide; NMR spectrometry; Mutation; Nodule
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/mic.0.26099-0

1 Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Apdo 1095, 41080 Sevilla, Spain
2 Departamento de Biología Celular, Facultad de Biología, Universidad de Sevilla, Av. Reina Mercedes s/n, 41012 Sevilla, Spain
3 Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Apdo 553, 41071 Sevilla, Spain
4 Department of Molecular Microbiology, John Innes Centre, Norwich NR4 7UH, UK
Correspondence José E. Ruiz-Sainz rsainz{at}us.es
The pleiotropic phenotype of an auxotrophic purL mutant (SVQ295) of Sinorhizobium fredii HH103 has been investigated. SVQ295 forms colonies that are translucent, produce more slime and absorb less Congo red than those of wild-type strain HH103. SVQ295 did not grow in minimal medium unless the culture was supplemented with thiamin and adenine or with thiamin and AICA-riboside (5-aminoimidazole-4-carboxamide 1- - D -ribofuranoside), an intermediate of purine biosynthesis. Bacterial cultures supplemented with AICA-riboside or adenine reached the same culture density, although the doubling time of SVQ295 cultures containing AICA-riboside was clearly longer. S. fredii SVQ295 induced pseudonodules on Glycine max and failed to nodulate six different legumes. On Glycyrrhiza uralensis , however, nodules showing nitrogenase activity and containing infected plant cells were formed. SVQ295 showed auto-agglutination when grown in liquid TY medium and its lipopolysaccharide (LPS) electrophoretic profile differed from that of its parental strain HH103-1. In addition, four monoclonal antibodies that recognize the LPS of S. fredii HH103 failed to recognize the LPS produced by SVQ295. In contrast, 1 H-NMR spectra of K-antigen capsular polysaccharides (KPS) produced by SVQ295 and the wild-type strain HH103 were similar. Co-inoculation of soybean plants with SVQ295 and SVQ116 (a nodA mutant derivative of HH103) produced nitrogen-fixing nodules that were only occupied by SVQ116.
Abbreviations: AICA-riboside, 5-aminoimidazole-4-carboxamide 1- - D -ribofuranoside; AICAR, 5-aminoimidazole-4-carboxamide ribonucleotide; KPS, K-antigen capsular polysaccharide; LCO, lipo-chitin oligosaccharide
The GenBank accession number for the sequence determined in this work is AF275718 .