[Regulation of gacA, dsbA and phoP/phoQ genes on the transcription of small RNA gene RsmZ in Pseudomonas fluorescens].
OBJECTIVE
Pseudomonas fluorescens 2P24 is a plant disease-suppressive bacterium isolated from wheat rhizosphere. Small RNA gene rsmZ in strain 2P24 plays an important role in the production of antibiotic 2,4-diacetylphloroglucinol (2,4-DAPG), a key factor in disease suppression.


OBJECTIVE
The aim of this study was to determine the influence of upstream regulators on the transcription of rsmZ.


METHODS
A reporting vector was constructed by fusing the promoter region of rsmZ gene with a promoterless lacZ gene on plasmid pRK970Km. The resulting plasmid was introduced into several regulatory gene mutants and the corresponding effects on RsmZ transcription were investigated.


RESULTS
The results indicated that a response regulator gene gacA from GacS/GacA two-component system positively regulated the transcription of RsmZ, whereas the oxidoreductase gene dsbA negatively regulated RsmZ expression. Furthermore, mutation on PhoP/PhoQ two-component system resulted in the delay of RsmZ transcription.


CONCLUSIONS
Our study suggests that the rsmZ gene in strain 2P24 transcripts under the pleiotropic regulation of a number of upstream genes, and may be involved in a more complex signal transduction cascade than that we have known.
Jiang
Weifang
W
Department of Plant Pathology, China Agricultural University, Beijing 100193, China. weifangjiang@gmail.com
Wu
Xiaogang
X
Yan
Qing
Q
Zhang
Liqun
L
D054742:Acyl-Butyrolactones; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology; D001483:Base Sequence; D029968:Escherichia coli Proteins / Q000235:genetics / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial; D005809:Genes, Regulator; D008969:Molecular Sequence Data; D010696:Phloroglucinol / Q000031:analogs & derivatives / Q000494:pharmacology; D019704:Protein Disulfide-Isomerases / Q000235:genetics / Q000502:physiology; D011551:Pseudomonas fluorescens / Q000235:genetics* / Q000378:metabolism; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000502:physiology*
D054742:Acyl-Butyrolactones; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C091100:GacA protein, Bacteria; C079792:PhoQ protein, Bacteria; D012329:RNA, Bacterial; C061064:PhoP protein, Bacteria; C059817:2,4-diacetylphloroglucinol; D010696:Phloroglucinol; D019704:Protein Disulfide-Isomerases; C526648:dsbA protein, E coli