title: PilG is Involved in the Regulation of Twitching Motility and Antifungal Antibiotic Biosynthesis in the Biological Control Agent Lysobacter enzymogenes.
abstract: Lysobacter enzymogenes strain C3 is a gliding bacterium which produces the antifungal secondary metabolite heat-stable antifungal factor (HSAF) and type IV pilus (T4P) as important mechanisms in biological control activity against fungal pathogens. To date, the regulators that control HSAF biosynthesis and T4P-dependent twitching motility in L. enzymogenes are poorly explored. In the present study, we addressed the role of pilG in the regulation of these two traits in L. enzymogenes. PilG of L. enzymogenes was found to be a response regulator, commonly known as a component of a two-component transduction system. Mutation of pilG in strain C3 abolished its ability to display spreading colony phenotype and cell movement at the colony margin, which is indicative of twitching motility; hence, PilG positively regulates twitching motility in L. enzymogenes. Mutation of pilG also enhanced HSAF production and the transcription of its key biosynthetic gene hsaf pks/nrps, suggesting that PilG plays a negative regulatory role in HSAF biosynthesis. This finding represents the first demonstration of the regulator PilG having a role in secondary metabolite biosynthesis in bacteria. Collectively, our results suggest that key ecological functions (HSAF production and twitching motility) in L. enzymogenes strain C3 are regulated in opposite directions by the same regulatory protein, PilG.
authors.affiliation: First, second, third, and fifth authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education; fourth author: Department of Chemistry, University of Nebraska-Lincoln, 68588; fifth author: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China; and sixth author: Department of Plant Pathology, University of Nebraska-Lincoln.
authors.forename: Xue
authors.initials: X
authors.lastname: Zhou
authors.affiliation: First, second, third, and fifth authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education; fourth author: Department of Chemistry, University of Nebraska-Lincoln, 68588; fifth author: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China; and sixth author: Department of Plant Pathology, University of Nebraska-Lincoln.
authors.forename: Guoliang
authors.initials: G
authors.lastname: Qian
authors.affiliation: First, second, third, and fifth authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education; fourth author: Department of Chemistry, University of Nebraska-Lincoln, 68588; fifth author: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China; and sixth author: Department of Plant Pathology, University of Nebraska-Lincoln.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: First, second, third, and fifth authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education; fourth author: Department of Chemistry, University of Nebraska-Lincoln, 68588; fifth author: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China; and sixth author: Department of Plant Pathology, University of Nebraska-Lincoln.
authors.forename: Liangcheng
authors.initials: L
authors.lastname: Du
authors.affiliation: First, second, third, and fifth authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education; fourth author: Department of Chemistry, University of Nebraska-Lincoln, 68588; fifth author: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China; and sixth author: Department of Plant Pathology, University of Nebraska-Lincoln.
authors.forename: Fengquan
authors.initials: F
authors.lastname: Liu
authors.affiliation: First, second, third, and fifth authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education; fourth author: Department of Chemistry, University of Nebraska-Lincoln, 68588; fifth author: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China; and sixth author: Department of Plant Pathology, University of Nebraska-Lincoln.
authors.forename: Gary Y
authors.initials: GY
authors.lastname: Yuen
mesh_terms: D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D061046:Biological Control Agents; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000378:metabolism; D053528:Lysobacter / Q000235:genetics* / Q000502:physiology; D008827:Microbiological Phenomena; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D010935:Plant Diseases / Q000382:microbiology*; D016415:Sequence Alignment; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; D001426:Bacterial Proteins; D061046:Biological Control Agents; D014157:Transcription Factors