title: SlyA regulates motA and motB, virulence and stress-related genes under conditions induced by the PhoP-PhoQ system in Dickeya dadantii 3937.
abstract: We previously showed that SlyA of Dickeya dadantii 3937 plays an important role in virulence toward plants, and that the ΔslyA mutant is hypermotile, whereas flagellum synthesis and flagellin production are indistinguishable from the wild type. Here we show that motility factors, including the distance of continuous directed movement, time for that movement and speed, were significantly higher in the ΔslyA mutant than in the wild type. Remarkably, transcription levels of motA and motB, that are involved in flagellar rotation, were elevated in the ΔslyA mutant, suggesting that the mutant's hypermotility was due to an increase in flagellar rotation. In low (10 μM) magnesium medium that activates the PhoP-PhoQ system, growth and virulence of the ΔslyA mutant were much lower than for the wild type; expression of motA, motB, mgtA, pelA, pelB, pelC, pelD, pelE, pelI, indA, tolC, sodC, acsA and hrpN were also reduced in the mutant. Interestingly, motA, motB, pelD, pelE, pelI, sodC and indA were also reduced in phoP and phoQ mutants. Because the SlyA protein directly binds to the promoter region of PhoP, SlyA regulates virulence by controlling multiple pathogenicity-related genes directly and/or at least by controlling PhoP in D. dadantii 3937 when magnesium is low.
authors.affiliation: Faculty of Agriculture, Shizuoka University, 836 Ohya, Suruga-Ku, Shizuoka 422-8529, Japan; Department of Environmental Science, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur 1706, Bangladesh.
authors.forename: Md Manjurul
authors.initials: MM
authors.lastname: Haque
authors.affiliation: Faculty of Agriculture, Shizuoka University, 836 Ohya, Suruga-Ku, Shizuoka 422-8529, Japan. Electronic address: ahhirat@ipc.shizuoka.ac.jp.
authors.forename: Hisae
authors.initials: H
authors.lastname: Hirata
authors.affiliation: Faculty of Agriculture, Shizuoka University, 836 Ohya, Suruga-Ku, Shizuoka 422-8529, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Tsuyumu
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004755:Enterobacteriaceae / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D005407:Flagella / Q000235:genetics / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial; D008278:Magnesium Sulfate / Q000378:metabolism; D009154:Mutation; D013312:Stress, Physiological; D014158:Transcription, Genetic; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; C063010:MotA protein, Bacteria; C064779:MotB protein, Bacteria; C079792:PhoQ protein, Bacteria; C061064:PhoP protein, Bacteria; D008278:Magnesium Sulfate
keywords: Dickeya dadantii 3937; Gene expression; Low magnesium; Motility; PhoP-PhoQ; SlyA