Molecular identification of Azospirillum spp.: limitations of 16S rRNA and qualities of rpoD as genetic markers
Since their discovery, plant-growth promoting rhizobacteria from the genus Azospirillum have been sub-jected to intensive research due to their biotechnological potential as crop inoculants. Phylogeneticanalysis of Azospirillum spp. is carried out by 16S rRNA sequencing almost exclusively, but incon...
| Autores principales: | , , , |
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| Formato: | info:ar-repo/semantics/artículo |
| Lenguaje: | Inglés |
| Publicado: |
2017
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| Materias: | |
| Acceso en línea: | http://hdl.handle.net/20.500.12123/1032 http://www.sciencedirect.com/science/article/pii/S0944501316307327?via%3Dihub https://doi.org/10.1016/j.micres.2016.11.009 |
| Sumario: | Since their discovery, plant-growth promoting rhizobacteria from the genus Azospirillum have been sub-jected to intensive research due to their biotechnological potential as crop inoculants. Phylogeneticanalysis of Azospirillum spp. is carried out by 16S rRNA sequencing almost exclusively, but inconsis-tencies and low confidence often arise when working with close species. In this work, it was observedthat these difficulties might be explained by a high number of rRNA operons with considerable inter-genic variability within Azospirillum genomes. To search for alternative genetic markers from a list ofhousekeeping genes, the correlation between pairwise gene and whole-genome similarities was exam-ined. Due to its good performance, rpoD was selected for further analyses. Genus-specific primers for thePCR-amplification and sequencing of rpoD from Azospirillum spp. were designed and tested on 16 typestrains of different species. The sequences obtained were used for inferring a phylogenetic tree of thegenus, which was in turn used as a reference to successfully identify a collection of 31 azospirilla iso-lated from many different locations of Argentine. In addition, several strains that might represent novelspecies were detected. The results indicate that the sequencing of rpoD is a suitable alternative methodfor a confident molecular identification in Azospirillum spp. |
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