Present address: Elías J. Mongiardini, Laboratori Genètica Molecular Bacteriana, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
Analysis of the role of the two flagella of Bradyrhizobium japonicum in competition for nodulation of soybean
Article first published online: 26 APR 2011
© 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Microbiology Letters
Volume 319, Issue 2, pages 133–139, June 2011
How to Cite
Althabegoiti, M. J., Covelli, J. M., Pérez-Giménez, J., Quelas, J. I., Mongiardini, E. J., López, M. F., López-García, S. L. and Lodeiro, A. R. (2011), Analysis of the role of the two flagella of Bradyrhizobium japonicum in competition for nodulation of soybean. FEMS Microbiology Letters, 319: 133–139. doi: 10.1111/j.1574-6968.2011.02280.x
Editor: Juan Imperial
- Issue published online: 17 MAY 2011
- Article first published online: 26 APR 2011
- Accepted manuscript online: 6 APR 2011 08:21AM EST
- Received 1 December 2010; revised 23 March 2011; accepted 24 March 2011., Final version published online 26 April 2011.
- water content;
Bradyrhizobium japonicum has two types of flagella. One has thin filaments consisting of the 33-kDa flagellins FliCI and FliCII (FliCI-II) and the other has thick filaments consisting of the 65-kDa flagellins FliC1, FliC2, FliC3, and FliC4 (FliC1-4). To investigate the roles of each flagellum in competition for nodulation, we obtained mutants deleted in fliCI-II and/or fliC1-4 in the genomic backgrounds of two derivatives from the reference strain USDA 110: the streptomycin-resistant derivative LP 3004 and its more motile derivative LP 3008. All mutations diminished swimming motility. When each mutant was co-inoculated with the parental strain on soybean plants cultivated in vermiculite either at field capacity or flooded, their competitiveness differed according to the flagellin altered. ΔfliCI-II mutants were more competitive, occupying 64–80% of the nodules, while ΔfliC1-4 mutants occupied 45–49% of the nodules. Occupation by the nonmotile double mutant decreased from 55% to 11% as the water content of the vermiculite increased from 85% to 95% field capacity to flooding. These results indicate that the influence of motility on competitiveness depended on the water status of the rooting substrate.