Improved salt tolerance of Synechococcus elongatus PCC 7942 by heterologous synthesis of compatible solute ectoine

In order to explore the effect of introducing the ectoine synthesis module in Synechococcus elongatus PCC 7942 on the global regulation of the strain under high-salt environment. The ectoine synthesis module was introduced at the Synpcc7942_0808 locus to obtain the Syn7942/?sps-ect strain that lacked sucrose synthesis and could synthesize ectoine. Comparative transcriptomic analysis was performed on WT and Syn7942/?sps-ect under 0 mM and 300 mM NaCl conditions. Overall design: WT and Syn7942/?sps-ect were cultured in BG11 medium with 0 mM as control-1 and control-2 and 300 mM NaCl as experimental-1 and experimental-2, respectively. On the fourth day, samples were collected for transcriptome sequencing and data analysis.