title: FleQ coordinates flagellum-dependent and -independent motilities in Pseudomonas syringae pv. tomato DC3000.
abstract: Motility plays an essential role in bacterial fitness and colonization in the plant environment, since it favors nutrient acquisition and avoidance of toxic substances, successful competition with other microorganisms, the ability to locate the preferred hosts, access to optimal sites within them, and dispersal in the environment during the course of transmission. In this work, we have observed that the mutation of the flagellar master regulatory gene, fleQ, alters bacterial surface motility and biosurfactant production, uncovering a new type of motility for Pseudomonas syringae pv. tomato DC3000 on semisolid surfaces. We present evidence that P. syringae pv. tomato DC3000 moves over semisolid surfaces by using at least two different types of motility, namely, swarming, which depends on the presence of flagella and syringafactin, a biosurfactant produced by this strain, and a flagellum-independent surface spreading or sliding, which also requires syringafactin. We also show that FleQ activates flagellum synthesis and negatively regulates syringafactin production in P. syringae pv. tomato DC3000. Finally, it was surprising to observe that mutants lacking flagella or syringafactin were as virulent as the wild type, and only the simultaneous loss of both flagella and syringafactin impairs the ability of P. syringae pv. tomato DC3000 to colonize tomato host plants and cause disease.
authors: Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain.
authors: Joaquina
authors: J
authors: Nogales
authors: Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain.
authors: Paola
authors: P
authors: Vargas
authors: Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain.
authors: Gabriela A
authors: GA
authors: Farias
authors: Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain.
authors: Adela
authors: A
authors: Olmedilla
authors: Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain.
authors: Juan
authors: J
authors: Sanjuán
authors: Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain maritrini.gallegos@eez.csic.es.
authors: María-Trinidad
authors: MT
authors: Gallegos
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D005407:Flagella / Q000235:genetics / Q000502:physiology*; D008124:Locomotion; D018551:Solanum lycopersicum; D009154:Mutation; D001678:Organelle Biogenesis; D010935:Plant Diseases / Q000382:microbiology; D044224:Pseudomonas syringae / Q000235:genetics / Q000502:physiology*; D013501:Surface-Active Agents / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D013501:Surface-Active Agents; D015534:Trans-Activators