Microarray transcriptional profiling of Arctic Mesorhizobium strain N33 at low temperature provides insights into cold adaption strategies
Abstract Background Arctic Mesorhizobium strain N33 was isolated from nodules of the legume Oxytropis arctobia in Canada’s eastern Arctic. This symbiotic bacterium can grow at temperatures ranging from 0 to 30 °C, fix nitrogen at 10 °C, and is one of the best known cold-adapted rhizobia. Despite the...
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ftbiomed:oai:biomedcentral.com:s12864-015-1611-4 2023-05-15T14:46:05+02:00 Microarray transcriptional profiling of Arctic Mesorhizobium strain N33 at low temperature provides insights into cold adaption strategies Ghobakhlou, Abdollah-Fardin Johnston, Anne Harris, Linda Antoun, Hani Laberge, Serge 2015-05-15 http://www.biomedcentral.com/1471-2164/16/383 en eng BioMed Central Ltd. http://www.biomedcentral.com/1471-2164/16/383 Copyright 2015 Ghobakhlou et al.; licensee BioMed Central. α-proteobacteria Genomic library Microarray Gene expression Transcriptomics Quantitative PCR Cold adaptation Nitrogen fixation Arctic Mesorhizobium Research article 2015 ftbiomed 2015-05-16T23:56:35Z Abstract Background Arctic Mesorhizobium strain N33 was isolated from nodules of the legume Oxytropis arctobia in Canada’s eastern Arctic. This symbiotic bacterium can grow at temperatures ranging from 0 to 30 °C, fix nitrogen at 10 °C, and is one of the best known cold-adapted rhizobia. Despite the economic potential of this bacterium for northern regions, the key molecular mechanisms of its cold adaptation remain poorly understood. Results Using a microarray printed with 5760 Arctic Mesorhizobium genomic clones, we performed a partial transcriptome analysis of strain N33 grown under eight different temperature conditions, including both sustained and transient cold treatments, compared with cells grown at room temperature. Cells treated under constant (4 and 10 °C) low temperatures expressed a prominent number of induced genes distinct from cells treated to short-term cold-exposure (<60 min), but exhibited an intermediate expression profile when exposed to a prolonged cold exposure (240 min). The most prominent up-regulated genes encode proteins involved in metabolite transport, transcription regulation, protein turnover, oxidoreductase activity, cryoprotection (mannitol, polyamines), fatty acid metabolism, and membrane fluidity. The main categories of genes affected in N33 during cold treatment are sugar transport and protein translocation, lipid biosynthesis, and NADH oxidoreductase (quinone) activity. Some genes were significantly down-regulated and classified in secretion, energy production and conversion, amino acid transport, cell motility, cell envelope and outer membrane biogenesis functions. This might suggest growth cessation or reduction, which is an important strategy to adjust cellular function and save energy under cold stress conditions. Conclusion Our analysis revealed a complex series of changes associated with cold exposure adaptation and constant growth at low temperatures. Moreover, it highlighted some of the strategies and different physiological states that Mesorhizobium strain N33 has developed to adapt to the cold environment of the Canadian high Arctic and has revealed candidate genes potentially involved in cold adaptation. Article in Journal/Newspaper Arctic BioMed Central Arctic |
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BioMed Central |
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ftbiomed |
language |
English |
topic |
α-proteobacteria Genomic library Microarray Gene expression Transcriptomics Quantitative PCR Cold adaptation Nitrogen fixation Arctic Mesorhizobium |
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α-proteobacteria Genomic library Microarray Gene expression Transcriptomics Quantitative PCR Cold adaptation Nitrogen fixation Arctic Mesorhizobium Ghobakhlou, Abdollah-Fardin Johnston, Anne Harris, Linda Antoun, Hani Laberge, Serge Microarray transcriptional profiling of Arctic Mesorhizobium strain N33 at low temperature provides insights into cold adaption strategies |
topic_facet |
α-proteobacteria Genomic library Microarray Gene expression Transcriptomics Quantitative PCR Cold adaptation Nitrogen fixation Arctic Mesorhizobium |
description |
Abstract Background Arctic Mesorhizobium strain N33 was isolated from nodules of the legume Oxytropis arctobia in Canada’s eastern Arctic. This symbiotic bacterium can grow at temperatures ranging from 0 to 30 °C, fix nitrogen at 10 °C, and is one of the best known cold-adapted rhizobia. Despite the economic potential of this bacterium for northern regions, the key molecular mechanisms of its cold adaptation remain poorly understood. Results Using a microarray printed with 5760 Arctic Mesorhizobium genomic clones, we performed a partial transcriptome analysis of strain N33 grown under eight different temperature conditions, including both sustained and transient cold treatments, compared with cells grown at room temperature. Cells treated under constant (4 and 10 °C) low temperatures expressed a prominent number of induced genes distinct from cells treated to short-term cold-exposure (<60 min), but exhibited an intermediate expression profile when exposed to a prolonged cold exposure (240 min). The most prominent up-regulated genes encode proteins involved in metabolite transport, transcription regulation, protein turnover, oxidoreductase activity, cryoprotection (mannitol, polyamines), fatty acid metabolism, and membrane fluidity. The main categories of genes affected in N33 during cold treatment are sugar transport and protein translocation, lipid biosynthesis, and NADH oxidoreductase (quinone) activity. Some genes were significantly down-regulated and classified in secretion, energy production and conversion, amino acid transport, cell motility, cell envelope and outer membrane biogenesis functions. This might suggest growth cessation or reduction, which is an important strategy to adjust cellular function and save energy under cold stress conditions. Conclusion Our analysis revealed a complex series of changes associated with cold exposure adaptation and constant growth at low temperatures. Moreover, it highlighted some of the strategies and different physiological states that Mesorhizobium strain N33 has developed to adapt to the cold environment of the Canadian high Arctic and has revealed candidate genes potentially involved in cold adaptation. |
format |
Article in Journal/Newspaper |
author |
Ghobakhlou, Abdollah-Fardin Johnston, Anne Harris, Linda Antoun, Hani Laberge, Serge |
author_facet |
Ghobakhlou, Abdollah-Fardin Johnston, Anne Harris, Linda Antoun, Hani Laberge, Serge |
author_sort |
Ghobakhlou, Abdollah-Fardin |
title |
Microarray transcriptional profiling of Arctic Mesorhizobium strain N33 at low temperature provides insights into cold adaption strategies |
title_short |
Microarray transcriptional profiling of Arctic Mesorhizobium strain N33 at low temperature provides insights into cold adaption strategies |
title_full |
Microarray transcriptional profiling of Arctic Mesorhizobium strain N33 at low temperature provides insights into cold adaption strategies |
title_fullStr |
Microarray transcriptional profiling of Arctic Mesorhizobium strain N33 at low temperature provides insights into cold adaption strategies |
title_full_unstemmed |
Microarray transcriptional profiling of Arctic Mesorhizobium strain N33 at low temperature provides insights into cold adaption strategies |
title_sort |
microarray transcriptional profiling of arctic mesorhizobium strain n33 at low temperature provides insights into cold adaption strategies |
publisher |
BioMed Central Ltd. |
publishDate |
2015 |
url |
http://www.biomedcentral.com/1471-2164/16/383 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_relation |
http://www.biomedcentral.com/1471-2164/16/383 |
op_rights |
Copyright 2015 Ghobakhlou et al.; licensee BioMed Central. |
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1766317356997410816 |