Transcriptional response of Microcystis aeruginosa to the recruitment promoting-benthic bacteria

Blooms of Microcystis aeruginosa occur frequently in many freshwater ecosystems around the world, but the mechanism of recovery has not been fully understood. In our previous study, three benthic bacterial species (E.sp013, Ba.spD06, and Ba.spD24) were identified capable of promoting the recruitment of M. aeruginosa. Here, we further investigated the transcriptional response of M. aeruginosa to the benthic bacteria in early phase of recruitment by means of RNA-Seq analysis. In total, 5 803 803 unigenes on average length of 404 bp were obtained from the transcriptome of M. aeruginosa. There were 54 982 unigenes identified as benthic bacteria-responsive unigenes based on the expression level analysis. Results of the protein-protein interaction analysis (PPI) show that the hub genes of the benthic bacteria responsive unigenes mediated network were ribosomal proteins of 30S and 50S, and the most significant functional module of the network was related to the ribosome. Both the unigenes encoding the translation initiation factors (IF-2, IF-3) and elongation factors (lepA, fusA, and tufA) were up-regulated to respond benthic bacteria. Therefore, it indicates that the benthic bacteria have a positive influence on activating the ribosome during the early recovery stage of M. aeruginosa.