vfr, A Global Regulatory Gene, is Required for Pyrrolnitrin but not for Phenazine-1-carboxylic Acid Biosynthesis in Pseudomonas chlororaphis G05

The Plant Pathology Journal

Xia Wu¹  Le Kai¹  Qiuning He¹  Longshuo Sun¹  Yanhua Wang¹  Xiaoyan Chi¹  Kailu Zhang¹  Kewen Wang¹  Weihai Xie¹  Jinxiu Tang¹  Yihe Ge¹  Xiuying Hao² 

[1] Department of Applied and Environmental Microbiology, School of Life Sciences, Ludong University, Yantai 264025, China;Institute of Applied Microbiology, Xinjiang Academy of Agricultural Sciences, Urumqi 830001, China;

关键词: P. chlororaphis;    phenazine-1-carboxylic acid;    pyrrolnitrin;    regulation;    Vfr;   

DOI  :  10.5423/PPJ.OA.01.2019.0011

来源: DOAJ

【 摘 要 】

In our previous study, pyrrolnitrin produced in Pseudomonas chlororaphis G05 plays more critical role in suppression of mycelial growth of some fungal pathogens that cause plant diseases in agriculture. Although some regulators for pyrrolnitrin biosynthesis were identified, the pyrrolnitrin regulation pathway was not fully constructed. During our screening novel regulator candidates, we obtained a white conjugant G05W02 while transposon mutagenesis was carried out between a fusion mutant G05ΔphzΔprn::lacZ and E. coli S17-1 (pUT/mini-Tn5Kan). By cloning and sequencing of the transposon-flanking DNA fragment, we found that a vfr gene in the conjugant G05W02 was disrupted with mini-Tn5Kan. In one other previous study on P. fluorescens, however, it was reported that the deletion of the vfr caused increased production of pyrrolnitrin and other antifungal metabolites. To confirm its regulatory function, we constructed the vfr-knockout mutant G05Δvfr and G05ΔphzΔprn::lacZΔvfr. By quantifying β-galactosidase activities, we found that deletion of the vfr decreased the prn operon expression dramatically. Meanwhile, by quantifying pyrrolnitrin production in the mutant G05Δvfr, we found that deficiency of the Vfr caused decreased pyrrolnitrin production. However, production of phenazine-1-carboxylic acid was same to that in the wild-type strain G05. Taken together, Vfr is required for pyrrolnitrin but not for phenazine-1-carboxylic acid biosynthesis in P. chlororaphis G05.

【 授权许可】

Unknown