Construction of Pseudomonas aeruginosa M18 rsmY mutant and its different regulation on PCA and Plt biosynthesis

Abstract:

[Objective] Small RNAs (sRNAs) regulate various genes expression, which involved in primary and secondary metabolism, quorum sensing system and a variety of toxins factors in various Pseudomonas spp.. Through studying the different role of RsmY on regulation of the two antibiotics phenazine-1-carboxylic acid (PCA) and Pyoluteorin (Plt) in the plant rhizosphere growth-promoting Pseudomonas aeruginosa M18, the results were to shed light on the pathways involved in secondary metabolism and provided some theoretical basis for building high-yield engineering strains. [Methods] The rsmY inactivated mutant M18RY was constructed by homologous recombination, and gene over-expression experiment and lacZ gene fusion report analysis were carried out to investigate the regulatory mechanisms involved in RsmY. [Results] PCA and Plt production were respectively assayed in wild type M18 and mutant M18RY strains. Compared with that in wild type M18, PCA production in rsmY mutant had a 5-fold increase, but Plt production in M18RY had an 8-fold decrease. The results could be confirmed identified by Gene rsmY over-expression experiment. Moreover, lacZ gene fusion report analysis further clarified that RsmY strongly up-regulated PCA biosynthesis via phzA2-G2 gene cluster. [Conclusion] Small RNA RsmY distinctively regulates the PCA and Plt biosynthesis.

Key words:Pseudomonas aeruginosa M18, rsmY, Phenazine-1-carboxylic acid, Pyoluteorin