Genomic features separating ten strains of Neorhizobium galegae with different symbiotic phenotypes

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Background
The symbiotic phenotype of Neorhizobium galegae, with strains specifically fixing nitrogen with either Galega orientalis or G. officinalis, has made it a target in research on determinants of host specificity in nitrogen fixation. The genomic differences between representative strains of the two symbiovars are, however, relatively small. This introduced a need for a dataset representing a larger bacterial population in order to make better conclusions on characteristics typical for a subset of the species. In this study, we produced draft genomes of eight strains of N. galegae having different symbiotic phenotypes, both with regard to host specificity and nitrogen fixation efficiency. These genomes were analysed together with the previously published complete genomes of N. galegae strains HAMBI 540T and HAMBI 1141.

Results
The results showed that the presence of an additional rpoN sigma factor gene in the symbiosis gene region is a characteristic specific to symbiovar orientalis, required for nitrogen fixation. Also the nifQ gene was shown to be crucial for functional symbiosis in both symbiovars. Genome-wide analyses identified additional genes characteristic of strains of the same symbiovar and of strains having similar plant growth promoting properties on Galega orientalis. Many of these genes are involved in transcriptional regulation or in metabolic functions.

Conclusions
The results of this study confirm that the only symbiosis-related gene that is present in one symbiovar of N. galegae but not in the other is an rpoN gene. The specific function of this gene remains to be determined, however. New genes that were identified as specific for strains of one symbiovar may be involved in determining host specificity, while others are defined as potential determinant genes for differences in efficiency of nitrogen fixation.
Original languageEnglish
Article number348
JournalBMC Genomics
Volume16
Number of pages14
ISSN1471-2164
DOIs
Publication statusPublished - 2 May 2015
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 1184 Genetics, developmental biology, physiology
  • 1183 Plant biology, microbiology, virology
  • 219 Environmental biotechnology

Cite this

@article{87cf4fd4214a4c35a50acfd3355a6a5a,
title = "Genomic features separating ten strains of Neorhizobium galegae with different symbiotic phenotypes",
abstract = "BackgroundThe symbiotic phenotype of Neorhizobium galegae, with strains specifically fixing nitrogen with either Galega orientalis or G. officinalis, has made it a target in research on determinants of host specificity in nitrogen fixation. The genomic differences between representative strains of the two symbiovars are, however, relatively small. This introduced a need for a dataset representing a larger bacterial population in order to make better conclusions on characteristics typical for a subset of the species. In this study, we produced draft genomes of eight strains of N. galegae having different symbiotic phenotypes, both with regard to host specificity and nitrogen fixation efficiency. These genomes were analysed together with the previously published complete genomes of N. galegae strains HAMBI 540T and HAMBI 1141. ResultsThe results showed that the presence of an additional rpoN sigma factor gene in the symbiosis gene region is a characteristic specific to symbiovar orientalis, required for nitrogen fixation. Also the nifQ gene was shown to be crucial for functional symbiosis in both symbiovars. Genome-wide analyses identified additional genes characteristic of strains of the same symbiovar and of strains having similar plant growth promoting properties on Galega orientalis. Many of these genes are involved in transcriptional regulation or in metabolic functions. ConclusionsThe results of this study confirm that the only symbiosis-related gene that is present in one symbiovar of N. galegae but not in the other is an rpoN gene. The specific function of this gene remains to be determined, however. New genes that were identified as specific for strains of one symbiovar may be involved in determining host specificity, while others are defined as potential determinant genes for differences in efficiency of nitrogen fixation.",
keywords = "1184 Genetics, developmental biology, physiology, 1183 Plant biology, microbiology, virology, 219 Environmental biotechnology",
author = "{\"O}sterman, {Janina Maria} and Mousavi, {Seyed Abdollah} and Koskinen, {Jani Patrik} and Paulin, {Lars G{\"o}ran} and Lindstr{\"o}m, {Anna Kristina}",
year = "2015",
month = "5",
day = "2",
doi = "10.1186/s12864-015-1576-3",
language = "English",
volume = "16",
journal = "BMC Genomics",
issn = "1471-2164",
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Genomic features separating ten strains of Neorhizobium galegae with different symbiotic phenotypes. / Österman, Janina Maria; Mousavi, Seyed Abdollah; Koskinen, Jani Patrik; Paulin, Lars Göran; Lindström, Anna Kristina.

In: BMC Genomics, Vol. 16, 348, 02.05.2015.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Genomic features separating ten strains of Neorhizobium galegae with different symbiotic phenotypes

AU - Österman, Janina Maria

AU - Mousavi, Seyed Abdollah

AU - Koskinen, Jani Patrik

AU - Paulin, Lars Göran

AU - Lindström, Anna Kristina

PY - 2015/5/2

Y1 - 2015/5/2

N2 - BackgroundThe symbiotic phenotype of Neorhizobium galegae, with strains specifically fixing nitrogen with either Galega orientalis or G. officinalis, has made it a target in research on determinants of host specificity in nitrogen fixation. The genomic differences between representative strains of the two symbiovars are, however, relatively small. This introduced a need for a dataset representing a larger bacterial population in order to make better conclusions on characteristics typical for a subset of the species. In this study, we produced draft genomes of eight strains of N. galegae having different symbiotic phenotypes, both with regard to host specificity and nitrogen fixation efficiency. These genomes were analysed together with the previously published complete genomes of N. galegae strains HAMBI 540T and HAMBI 1141. ResultsThe results showed that the presence of an additional rpoN sigma factor gene in the symbiosis gene region is a characteristic specific to symbiovar orientalis, required for nitrogen fixation. Also the nifQ gene was shown to be crucial for functional symbiosis in both symbiovars. Genome-wide analyses identified additional genes characteristic of strains of the same symbiovar and of strains having similar plant growth promoting properties on Galega orientalis. Many of these genes are involved in transcriptional regulation or in metabolic functions. ConclusionsThe results of this study confirm that the only symbiosis-related gene that is present in one symbiovar of N. galegae but not in the other is an rpoN gene. The specific function of this gene remains to be determined, however. New genes that were identified as specific for strains of one symbiovar may be involved in determining host specificity, while others are defined as potential determinant genes for differences in efficiency of nitrogen fixation.

AB - BackgroundThe symbiotic phenotype of Neorhizobium galegae, with strains specifically fixing nitrogen with either Galega orientalis or G. officinalis, has made it a target in research on determinants of host specificity in nitrogen fixation. The genomic differences between representative strains of the two symbiovars are, however, relatively small. This introduced a need for a dataset representing a larger bacterial population in order to make better conclusions on characteristics typical for a subset of the species. In this study, we produced draft genomes of eight strains of N. galegae having different symbiotic phenotypes, both with regard to host specificity and nitrogen fixation efficiency. These genomes were analysed together with the previously published complete genomes of N. galegae strains HAMBI 540T and HAMBI 1141. ResultsThe results showed that the presence of an additional rpoN sigma factor gene in the symbiosis gene region is a characteristic specific to symbiovar orientalis, required for nitrogen fixation. Also the nifQ gene was shown to be crucial for functional symbiosis in both symbiovars. Genome-wide analyses identified additional genes characteristic of strains of the same symbiovar and of strains having similar plant growth promoting properties on Galega orientalis. Many of these genes are involved in transcriptional regulation or in metabolic functions. ConclusionsThe results of this study confirm that the only symbiosis-related gene that is present in one symbiovar of N. galegae but not in the other is an rpoN gene. The specific function of this gene remains to be determined, however. New genes that were identified as specific for strains of one symbiovar may be involved in determining host specificity, while others are defined as potential determinant genes for differences in efficiency of nitrogen fixation.

KW - 1184 Genetics, developmental biology, physiology

KW - 1183 Plant biology, microbiology, virology

KW - 219 Environmental biotechnology

U2 - 10.1186/s12864-015-1576-3

DO - 10.1186/s12864-015-1576-3

M3 - Article

VL - 16

JO - BMC Genomics

JF - BMC Genomics

SN - 1471-2164

M1 - 348

ER -