首页|EppR, a new LysR-family transcription regulator, positively influences phenazine biosynthesis in the plant growth-promoting rhizobacterium Pseudomonas chlororaphis G05

EppR, a new LysR-family transcription regulator, positively influences phenazine biosynthesis in the plant growth-promoting rhizobacterium Pseudomonas chlororaphis G05

扫码查看
原文链接
  • NSTL
  • Elsevier
Pseudomonas chlororaphis G05 has the capability to repress the mycelial growth of many phytopathogenic fungi by producing and secreting certain antifungal compounds, including phenazines and pyrrolnitrin. Although some regulatory genes have been identified to be involved in antifungal metabolite production, the regulatory mechanism and pathway of phenazine-1-carboxylic acid biosynthesis remain poorly defined. To identify more new regulatory genes, we applied transposon mutagenesis with the chromosomal lacZ fusion strain G05 Delta phz:: lacZ as an acceptor. In the white conjugant colony G05W05, a novel transcriptional regulator gene, eppR, was verified to be interrupted by the transposon mini-Tn5Kan. To evaluate the specific function of eppR, we created a set of eppR-deletion mutants, including G05 Delta eppR, G05 Delta phz::lacZ Delta eppR and G05 Delta prn::lacZ Delta eppR. By quantifying the production of antifungal compounds and beta-galactosidase expression, we found that the expression of the phenazine biosynthetic gene cluster (phz) and the production of phenazine-1-carboxylic acid were markedly reduced in the absence of EppR. Moreover, the pathogen suppression test verified that the yield of phenazine-1carboxylic acid was significantly decreased when eppR was deleted in frame. At the same time, no changes in the expression of the phzI/phzR quorum-sensing (QS) system and the production of N-acyl homoserine lactones (AHLs) and pyrrolnitrin were found in the EppR-deficient mutant. In addition, chromosomal fusion analyses and quantitative real-time polymerase chain reaction (qRT-PCR) results also showed that EppR could positively mediate the expression of the phz cluster at the posttranscriptional level. In summary, EppR is specifically essential for phenazine biosynthesis but not for pyrrolnitrin biosynthesis in P. chlororaphis.

Pseudomonas chlororaphisPhenazine-1-carboxylic acidTransposon mutagenesisLysR-family transcription regulatorTranscription factorPyrrolnitrinBIOLOGICAL-CONTROLBIOCONTROL AGENTSGENE-EXPRESSIONFLUORESCENSGACAPYRROLNITRINRNAACTIVATIONRESISTANCEPATHOGENS

Chi, Xiaoyan、Wang, Yanhua、Miao, Jing、Wang, Wei、Sun, Yanyang、Yu, Zhifen、Feng, Zhibin、Cheng, Shiwei、Chen, Lijuan、Ge, Yihe

展开 >

Ludong Univ

2022

10.1016/j.micres.2022.127050

Microbiological Research

Microbiological Research

EISCI
ISSN：0944-5013
年,卷(期)：2022.260
  • 66