Evolution of Goat’s Rue Rhizobia (Neorhizobium galegae): Analysis of Polymorphism of the Nitrogen Fixation and Nodule Formation Genes
Autor: | A. E. Tupikin, E. P. Chizhevskaya, T. S. Aksenova, E. S. Karasev, E. E. Andronov, Nikolay A Provorov |
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Rok vydání: | 2019 |
Předmět: |
0106 biological sciences
0303 health sciences food.ingredient biology Galega orientalis Single-nucleotide polymorphism biology.organism_classification 01 natural sciences Rhizobia 03 medical and health sciences food Officinalis Botany Neorhizobium Genetics Nitrogen fixation Gene 030304 developmental biology 010606 plant biology & botany Symbiotic bacteria |
Zdroj: | Russian Journal of Genetics. 55:263-266 |
ISSN: | 1608-3369 1022-7954 |
Popis: | The goat’s rue rhizobia (Neorhizobium galegae) represent a convenient model to study the evolution and speciation of symbiotic bacteria. This rhizobial species is composed of two biovars (bv. orientalis and bv. officinalis), which form N2-fixing nodules with certain species of goat’s rue (Galega orientalis and G. officinalis). The cross-inoculation between them results in the formation of nodules unable to fix nitrogen. On the basis of the data on the whole-genome sequencing, we studied the nucleotide polymorphism of 11 N. galegae strains isolated from the North Caucasus ecosystems, where G. orientalis has higher diversity than G. officinalis. The low level of differences in the polymorphism within the group of the sym genes in comparison with the nonsymbiotic genes can be associated with the active participation of host plants in the evolution of rhizobia. The intragenic polymorphism of bv. orientalis proved to be significantly higher than that of bv. officinalis. The level of polymorphism of nonsymbiotic genes was lower than that of the symbiotic genes, which are functionally more homogeneous. The divergence of the nitrogen fixation genes (nif/fix) is more pronounced than that of the nodule formation genes (nod) in the N. galegae biovars. These facts indicate the leading role of the host-specific nitrogen fixation in the evolution of the studied rizhobial species. |
Databáze: | OpenAIRE |
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