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A systems biology approach to investigate the response of Synechocystis sp. PCC6803 to a high salt environment.

Pandhal J, Noirel J, Wright PC, Biggs CA - Saline Syst. (2009)

Bottom Line: Differentially expressed proteins involved in metabolic responses were also analysed using the probabilitistic tool Mixed Model on Graphs (MMG), where the role of energy conversion through glycolysis and reducing power through pentose phosphate pathway were highlighted.This study demonstrates the effectiveness of using a systems biology approach in answering environmental, and in particular, salt adaptation questions in Synechocystis sp.PCC6803.

View Article: PubMed Central - HTML - PubMed

Affiliation: ChELSI Institute, Department of Chemical and Process Engineering, The University of Sheffield, Sheffield, UK. j.pandhal@sheffield.ac.uk

ABSTRACT

Background: Salt overloading during agricultural processes is causing a decrease in crop productivity due to saline sensitivity. Salt tolerant cyanobacteria share many cellular characteristics with higher plants and therefore make ideal model systems for studying salinity stress. Here, the response of fully adapted Synechocystis sp. PCC6803 cells to the addition of 6% w/v NaCl was investigated using proteomics combined with targeted analysis of transcripts.

Results: Isobaric mass tagging of peptides led to accurate relative quantitation and identification of 378 proteins, and approximately 40% of these were differentially expressed after incubation in BG-11 media supplemented with 6% salt for 9 days. Protein abundance changes were related to essential cellular functional alterations. Differentially expressed proteins involved in metabolic responses were also analysed using the probabilitistic tool Mixed Model on Graphs (MMG), where the role of energy conversion through glycolysis and reducing power through pentose phosphate pathway were highlighted. Temporal RT-qPCR experiments were also run to investigate protein expression changes at the transcript level, for 14 non-metabolic proteins. In 9 out of 14 cases the mRNA changes were in accordance with the proteins.

Conclusion: Synechocystis sp. PCC6803 has the ability to regulate essential metabolic processes to enable survival in high salt environments. This adaptation strategy is assisted by further regulation of proteins involved in non-metabolic cellular processes, supported by transcriptional and post-transcriptional control. This study demonstrates the effectiveness of using a systems biology approach in answering environmental, and in particular, salt adaptation questions in Synechocystis sp. PCC6803.

No MeSH data available.


Metabolic changes in salt adapted cells. A summary of metabolic changes occurring in Synechocystis cells adapted to 6% salt using iTRAQ-based global proteome analysis.
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Figure 3: Metabolic changes in salt adapted cells. A summary of metabolic changes occurring in Synechocystis cells adapted to 6% salt using iTRAQ-based global proteome analysis.

Mentions: Due to the connection between high salt response and oxidative stress, this study prompts the question of the existence of producing and consuming pathways of NAD(P)H. Whereas superoxide dismutase is manifestly up-regulated in both Workflows (2.83 and 2.83 in Workflow 1, 2.44 and 2.36 in Workflow 2), further detoxification of H2O2 is not clearly up-regulated. Peroxidase is indeed found to be down-regulated (0.58 and 0.50 in Workflow 2), whereas the catalase is only mildly up-regulated (1.06 and 1.21 in Workflow 1, 1.45 and 1.39 in Workflow 2). Down-regulation of the oxidative phase of the pentose phosphate pathway could mean the depletion of reducing power, which could be compensated by photosynthesis. Figure 3 summarises the metabolic changes that occur in cells when adapted to 6% salt.


A systems biology approach to investigate the response of Synechocystis sp. PCC6803 to a high salt environment.

Pandhal J, Noirel J, Wright PC, Biggs CA - Saline Syst. (2009)

Metabolic changes in salt adapted cells. A summary of metabolic changes occurring in Synechocystis cells adapted to 6% salt using iTRAQ-based global proteome analysis.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2743698&req=5

Figure 3: Metabolic changes in salt adapted cells. A summary of metabolic changes occurring in Synechocystis cells adapted to 6% salt using iTRAQ-based global proteome analysis.
Mentions: Due to the connection between high salt response and oxidative stress, this study prompts the question of the existence of producing and consuming pathways of NAD(P)H. Whereas superoxide dismutase is manifestly up-regulated in both Workflows (2.83 and 2.83 in Workflow 1, 2.44 and 2.36 in Workflow 2), further detoxification of H2O2 is not clearly up-regulated. Peroxidase is indeed found to be down-regulated (0.58 and 0.50 in Workflow 2), whereas the catalase is only mildly up-regulated (1.06 and 1.21 in Workflow 1, 1.45 and 1.39 in Workflow 2). Down-regulation of the oxidative phase of the pentose phosphate pathway could mean the depletion of reducing power, which could be compensated by photosynthesis. Figure 3 summarises the metabolic changes that occur in cells when adapted to 6% salt.

Bottom Line: Differentially expressed proteins involved in metabolic responses were also analysed using the probabilitistic tool Mixed Model on Graphs (MMG), where the role of energy conversion through glycolysis and reducing power through pentose phosphate pathway were highlighted.This study demonstrates the effectiveness of using a systems biology approach in answering environmental, and in particular, salt adaptation questions in Synechocystis sp.PCC6803.

View Article: PubMed Central - HTML - PubMed

Affiliation: ChELSI Institute, Department of Chemical and Process Engineering, The University of Sheffield, Sheffield, UK. j.pandhal@sheffield.ac.uk

ABSTRACT

Background: Salt overloading during agricultural processes is causing a decrease in crop productivity due to saline sensitivity. Salt tolerant cyanobacteria share many cellular characteristics with higher plants and therefore make ideal model systems for studying salinity stress. Here, the response of fully adapted Synechocystis sp. PCC6803 cells to the addition of 6% w/v NaCl was investigated using proteomics combined with targeted analysis of transcripts.

Results: Isobaric mass tagging of peptides led to accurate relative quantitation and identification of 378 proteins, and approximately 40% of these were differentially expressed after incubation in BG-11 media supplemented with 6% salt for 9 days. Protein abundance changes were related to essential cellular functional alterations. Differentially expressed proteins involved in metabolic responses were also analysed using the probabilitistic tool Mixed Model on Graphs (MMG), where the role of energy conversion through glycolysis and reducing power through pentose phosphate pathway were highlighted. Temporal RT-qPCR experiments were also run to investigate protein expression changes at the transcript level, for 14 non-metabolic proteins. In 9 out of 14 cases the mRNA changes were in accordance with the proteins.

Conclusion: Synechocystis sp. PCC6803 has the ability to regulate essential metabolic processes to enable survival in high salt environments. This adaptation strategy is assisted by further regulation of proteins involved in non-metabolic cellular processes, supported by transcriptional and post-transcriptional control. This study demonstrates the effectiveness of using a systems biology approach in answering environmental, and in particular, salt adaptation questions in Synechocystis sp. PCC6803.

No MeSH data available.