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Series GSE50060 Query DataSets for GSE50060
Status Public on Sep 20, 2013
Title Gene expression changes in group 2 sigma factor mutant, ΔsigCDE, in standard growth conditions and after high-light treatment
Organism Synechocystis sp. PCC 6803
Experiment type Expression profiling by array
Summary Adjustment of gene expression during acclimation to stress conditions, such as bright light, in the cyanobacterium Synechocystis sp. PCC 6803 depends on four group 2 σ factors (SigB, SigC, SigD, SigE). A ∆sigCDE strain containing the stress responsive SigB as an only functional group 2 σ factor appears twice as resistant to photoinhibition of photosystem II (PSII) as the control strain. Microarray analyzes of the ∆sigCDE strain indicated that 77 genes in standard conditions and 79 genes in high light were differently expressed compared to the control strain. Analysis of possible photoprotective mechanisms revealed that high carotenoid content and up-regulation of the photoprotective flavodiiron operon flv4-sll0218-flv2 protected PSII in ∆sigCDE, while up-regulation of pgr5-like, hlipB or isiA genes in the mutant strain did not offer particular protection against photoinhibition. The photoinhibition resistance was lost if ∆sigCDE was grown in high CO2 where carotenoid and Flv4-Sll0218-Flv2 contents were low. Additionally, photoinhibition resistance of the ∆rpoZ strain (lacking the omega subunit of RNA polymerase) with very high carotenoid but only low Flv4-Sll0218-Flv2 content supported the importance of carotenoids in PSII protection. Carotenoids likely protect mainly via quenching of singlet oxygen but efficient non-photochemical quenching in ∆sigCDE might offer some additional protection. Comparison of photoinhibition kinetics in control, ∆sigCDE and ∆rpoZ strains showed that protection by the flavodiiron operon was most efficient during the first minutes of high-light illumination.
 
Overall design Cells from cyanobacteria Synechocystis sp. PCC 6803 named as control strain (CS) and group 2 sigma factor mutant ΔsigCDE (A730=1, 40 mL) were harvested directly from standard growth conditions (continuous illumination at the PPFD of 40 µmol m-2s-1, 32°C, ambient CO2) or after 30-min illumination a PPFD 750 µmol m-2s-1. From three to four independent experiments were performed at each conditions.
 
Contributor(s) Tyystjarvi T, Hakkila K, Matthijs HC
Citation(s) 24009334
Submission date Aug 21, 2013
Last update date Jul 23, 2018
Contact name Taina Tyystjarvi
E-mail taityy@utu.fi
Organization name University of Turku
Department Biochemistry
Lab Molecular Plant Biology
Street address Pharmacity/Itäinen Pitkäkatu 4 C, 6th floor
City Turku
ZIP/Postal code 20520
Country Finland
 
Platforms (1)
GPL17595 Agilent-016989 Synechocystis array [ORF version]
Samples (13)
GSM1213398 CS_standard_biol.rep1
GSM1213399 CS_standard_biol.rep2
GSM1213400 CS_standard_biol.rep3
Relations
BioProject PRJNA215900

Download family Format
SOFT formatted family file(s) SOFTHelp
MINiML formatted family file(s) MINiMLHelp
Series Matrix File(s) TXTHelp

Supplementary file Size Download File type/resource
GSE50060_RAW.tar 9.8 Mb (http)(custom) TAR (of TXT)
Raw data provided as supplementary file
Processed data included within Sample table

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