Pseudomonas aeruginosa is an opportunistic bacterium infecting humans,animals and plants.In terms of plants,it can cause soft rot,for example,in Arabidopsis thaliana(Thale cress)and Lactuca sativa(lettuce).On the other hand,P.aeruginosa can produce various phenazines,of which phenazine-1-carboxylic acid(PCA)is an important biopesticide with trade mark Shenqinmycin against a broad spectrum of plant diseases.Two-component systems in bacteria are important to sense environmental stimuli and regulate bacteria in response to environmental stimuli.As a model bacterium,P.aeruginosa has about 140 genes related to two-component systems.Therefore it is important to understand how those two-component systems respond to different environmental stimuli altogether,which will also help to enrich our knowledge on the production of PCA.In this study,the publicly available transcriptomic data generated from GPL84 platform from NIH Gene Expression Omnibus(GEO)in 104 publications have been analyzed using co-expression network.The results show the whole picture on how two-component system genes react to different environmental stimuli,and how these genes reorganized under different conditions.