small RNA of Synechocystis sp. PCC 6803 under ammonium stress
Wild type Synechocystis 6803 was cultured in 30 mM NH4Cl or 30 mM NaCl for 30 minutes (short-term) or 24 hours (long-term). Samples without stress served as the background control (BC). Three replicates were included in each group. Total RNAs were extracted via TRIzol Reagent (Invitrogen). RNA sample was quantified by Qubit Fluorometer (Thermo Fisher Scientific, USA) and the integrity of RNA was assessed by Bioanalyzer 2100 (Agilent, USA). The UMI (unique molecular identifier) adapters were added to both ends of RNA. The cDNA library was constructed by Small RNA Library Preparation Kit (Illumina, USA) and then subjected to sequencing at Illumina NovaSeq (Kangce SeqHealth, Wuhan, China)