||Prakash JS, Sinetova M, Zorina A, Kupriyanova E, Suzuki I, Murata N, Los DA.
||DNA supercoiling regulates the stress-inducible expression of genes in the cyanobacterium Synechocystis
||Mol Biosyst. 2009 Dec;5(12):1904-12
||Salt stress was achieved by the addition of 5 M NaCl in BG11 medium to a final concentration of 0.5 M to cell cultures for 30 min. Cold stress was given by placing culture tubes of cells that had been grown at 34 ºC in a water bath at 24 ºC for 30 min. Heat stress was provided by placing culture tubes of cells that had been grown at 34 ºC in a water bath at 44 ºC for 30 min. Upon treatment of Synechocystis cells with novobiocin to decrease the extent of negative supercoiling of DNA, cells were incubated for 30 min under growth conditions in the presence of novobiocin at 50 mg ml before application of cold, heat or salt stress.
||Glucose-tolerant (GT) strain of Synechocystis sp. PCC 6803 cells were cultured at 34 ºC in BG11 medium under continuous illumination with light from incandescent lamps at 70 mmol photons m 2 s 1 and were aerated with air that contained 1% CO2. For every treatment equal amounts of BG11 medium were added to control cultures to avoid the effect of dilution of the suspension on gene expression.