RpoS as an intermediate in RsmA-dependent regulation of secondary antifungal metabolites biosynthesis in Pseudomonas sp. M18.
To investigate the regulatory mechanism governing antifungal metabolite biosynthesis, two kinds of global regulator genes in Pseudomonas sp. M18, an rpoS and an rsmA gene, were cloned and mutated by inserting with an aacC1 cassette, respectively. Two mutants showed the same regulatory mode with repression of phenazine-1-carboxylic acid and remarkable enhancement of pyoluteorin. In the rpoS-mutant, a translational rsmA'-'lacZ fusion was expressed at the same level corresponding to that in the wild-type strain. In the rsmA-mutant, however, expression of the translational rpoS'-'lacZ fusion was only about 30% of that in the wild-type strain. The results indicated that the absence of RsmA leads to repression of the rpoS gene expression, which has further been confirmed with construction of chromosomal rpoS-lacZ fusion in the rsmA-mutant and the wild-type strain, respectively. The findings showed a new regulatory cascade controlling antifungal metabolite production in Pseudomonas sp. M18, suggesting that RpoS may serve as a mediator in RsmA-dependent regulation of secondary metabolite biosynthesis.
Ge
Yihe
Y
Department of Biological Science, Huaiyin Teachers College, Huaian, China. geyihe@126.com
Yang
Shude
S
Fang
Yanyu
Y
Yang
Runya
R
Mou
Daiying
D
Cui
Jinpeng
J
Wen
Lu
L
D000935:Antifungal Agents / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003470:Culture Media; D015964:Gene Expression Regulation, Bacterial; D009154:Mutation; D010619:Phenazines / Q000378:metabolism; D010636:Phenols / Q000378:metabolism; D011549:Pseudomonas / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D011758:Pyrroles / Q000378:metabolism; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism*
D000935:Antifungal Agents; D001426:Bacterial Proteins; D003470:Culture Media; D010619:Phenazines; D010636:Phenols; D011758:Pyrroles; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; C095468:RsmA protein, Erwinia carotovora; D012808:Sigma Factor; C095503:pyoluteorin; C069567:sigma factor KatF protein, Bacteria; C037165:1-phenazinecarboxylic acid