Roles of the Gac‐Rsm pathway in the regulation of phenazine biosynthesis in Pseudomonas chlororaphis 30‐84

摘要: The GacS/GacA two-component regulatory system activates the production of secondary metabolites including phenazines crucial for biological control activity in Pseudomonas chlororaphis 30-84. To better understand role Gac on phenazine regulation, transcriptomic analyses were conducted by comparing wild-type strain to a gacA mutant. RNA-seq analysis identified 771 genes under GacA control, many novel genes. Consistent with previous findings, biosynthetic significantly downregulated transcript abundances such as phzI, phzR, iopA, iopB, rpoS, and pip also reduced. Moreover, abundance three noncoding RNAs (ncRNAs) rsmX, rsmY, rsmZ was decreased mutation consistent presence consensus GacA-binding sites associated their promoters. Our results demonstrated that constitutive expression from non-gac regulated promoter resulted complete restoration N-acyl-homoserine lactone (AHL) well other gac-dependent gac mutants. RsmA RsmE investigated. Overexpression rsmE, but not rsmA, AHL P. chlororaphis, only rsmE bypassed requirement gene expression. In contrast, phzI/phzR quorum sensing did rescue mutant, indicating direct posttranscriptional On basis these results, we propose model illustrate hierarchic regulators modulated production. used identify additional may contribute capability