title: AmrZ regulates cellulose production in Pseudomonas syringae pv. tomato DC3000.
abstract: In Pseudomonas syringae pv. tomato DC3000, the second messenger c-di-GMP has been previously shown to stimulate pellicle formation and cellulose biosynthesis. A screen for genes involved in cellulose production under high c-di-GMP intracellular levels led to the identification of insertions in two genes, wssB and wssE, belonging to the Pto DC3000 cellulose biosynthesis operon wssABCDEFGHI. Interestingly, beside cellulose-deficient mutants, colonies with a rougher appearance than the wild type also arouse among the transposants. Those mutants carry insertions in amrZ, a gene encoding a transcriptional regulator in different Pseudomonas. Here, we provide evidence that AmrZ is involved in the regulation of bacterial cellulose production at transcriptional level by binding to the promoter region of the wssABCDEFGHI operon and repressing cellulose biosynthesis genes. Mutation of amrZ promotes wrinkly colony morphology, increased cellulose production and loss of motility in Pto DC3000. AmrZ regulon includes putative c-di-GMP metabolising proteins, like AdcA and MorA, which may also impact those phenotypes. Furthermore, an amrZ but not a cellulose-deficient mutant turned out to be impaired in pathogenesis, indicating that AmrZ is a key regulator of Pto DC3000 virulence probably by controlling bacterial processes other than cellulose production.
authors.affiliation: Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain.
authors.forename: Harold A
authors.initials: HA
authors.lastname: Prada-Ramírez
authors.affiliation: Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: Pérez-Mendoza
authors.affiliation: Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain.
authors.forename: Antonia
authors.initials: A
authors.lastname: Felipe
authors.affiliation: Department of Biology, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Martínez-Granero
authors.affiliation: Department of Biology, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Rivilla
authors.affiliation: Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Sanjuán
authors.affiliation: Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain.
authors.forename: María-Trinidad
authors.initials: MT
authors.lastname: Gallegos
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D002482:Cellulose / Q000096:biosynthesis*; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism; D018551:Solanum lycopersicum / Q000382:microbiology*; D016254:Mutagenesis, Insertional; D016297:Mutagenesis, Site-Directed; D009876:Operon; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000382:microbiology; D044224:Pseudomonas syringae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D018085:Regulon
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C062025:bis(3',5')-cyclic diguanylic acid; D002482:Cellulose; D005964:Glucosyltransferases; C076062:cellulose synthase (cyclic diguanylic acid); D006152:Cyclic GMP