title: Expression of nipP.w of Pectobacterium wasabiae is dependent on functional flgKL flagellar genes.
abstract: While flagellum-driven motility is hypothesized to play a role in the virulence of Pectobacterium species, there is no direct evidence that genes involved in flagellum assembly regulate the synthesis of virulence factors. The purpose of this study was to identify genes that affect the production or secretion of necrosis-inducing protein (Nip) in the strain SCC3193. Transposon mutagenesis of an RpoS strain overexpressing NipP.w was performed, and a mutant associated with decreased necrosis of tobacco leaves was detected. The mutant contained a transposon in the regulatory region upstream of the flagellar genes flgK and flgL. Additional mutants were generated related to the flagellar genes fliC and fliA. The mutation in flgKL, but not those in fliC and fliA, inhibited nipP.w transcription. Moreover, the regulatory effect of the flgKL mutation on nipP.w transcription was partially dependent on the Rcs phosphorelay. Secretion of NipP.w was also dependent on a type II secretion mechanism. Overall, the results of this study indicate that the flgKL mutation is responsible for reduced motility and lower levels of nipP.w expression.
authors.affiliation: Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, 23 Riia Street, Tartu 51010, Estonia.
authors.forename: Eve
authors.initials: E
authors.lastname: Laasik
authors.affiliation: Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, 23 Riia Street, Tartu 51010, Estonia.
authors.forename: Lee
authors.initials: L
authors.lastname: Põllumaa
authors.affiliation: Department of Agricultural Sciences, PO Box 27, 00014 University of Helsinki, Finland.
authors.forename: Miia
authors.initials: M
authors.lastname: Pasanen
authors.affiliation: Department of Agricultural Sciences, PO Box 27, 00014 University of Helsinki, Finland.
authors.forename: Laura
authors.initials: L
authors.lastname: Mattinen
authors.affiliation: Department of Agricultural Sciences, PO Box 27, 00014 University of Helsinki, Finland.
authors.forename: Minna
authors.initials: M
authors.lastname: Pirhonen
authors.affiliation: Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, 23 Riia Street, Tartu 51010, Estonia.
authors.forename: Andres
authors.initials: A
authors.lastname: Mäe
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D004251:DNA Transposable Elements; D015964:Gene Expression Regulation, Bacterial; D016254:Mutagenesis, Insertional; D044043:Pectobacterium / Q000235:genetics* / Q000378:metabolism* / Q000472:pathogenicity; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000382:microbiology; D014026:Nicotiana / Q000382:microbiology
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements