title: Characterization of the Xylella fastidiosa PD1671 gene encoding degenerate c-di-GMP GGDEF/EAL domains, and its role in the development of Pierce's disease.
abstract: Xylella fastidiosa is an important phytopathogenic bacterium that causes many serious plant diseases including Pierce's disease of grapevines. X. fastidiosa is thought to induce disease by colonizing and clogging xylem vessels through the formation of cell aggregates and bacterial biofilms. Here we examine the role in X. fastidiosa virulence of an uncharacterized gene, PD1671, annotated as a two-component response regulator with potential GGDEF and EAL domains. GGDEF domains are found in c-di-GMP diguanylate cyclases while EAL domains are found in phosphodiesterases, and these domains are for c-di-GMP production and turnover, respectively. Functional analysis of the PD1671 gene revealed that it affected multiple X. fastidiosa virulence-related phenotypes. A Tn5 PD1671 mutant had a hypervirulent phenotype in grapevines presumably due to enhanced expression of gum genes leading to increased exopolysaccharide levels that resulted in elevated biofilm formation. Interestingly, the PD1671 mutant also had decreased motility in vitro but did not show a reduced distribution in grapevines following inoculation. Given these responses, the putative PD1671 protein may be a negative regulator of X. fastidiosa virulence.
authors: Department of Plant Pathology and Plant Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America; Department of Biology, Hobart and William Smith Colleges Geneva, New York, United States of America.
authors: Luciana
authors: L
authors: Cursino
authors: Department of Plant Pathology and Plant Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America.
authors: Dusit
authors: D
authors: Athinuwat
authors: Department of Biology, Hobart and William Smith Colleges Geneva, New York, United States of America.
authors: Kelly R
authors: KR
authors: Patel
authors: Department of Plant Pathology and Plant Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America; Department of Biology, Hobart and William Smith Colleges Geneva, New York, United States of America.
authors: Cheryl D
authors: CD
authors: Galvani
authors: Department of Plant Pathology and Plant Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America.
authors: Paulo A
authors: PA
authors: Zaini
authors: Department of Plant Pathology and Plant Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America.
authors: Yaxin
authors: Y
authors: Li
authors: Department of Plant Pathology and Plant Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America.
authors: Leonardo
authors: L
authors: De La Fuente
authors: Department of Plant Pathology and Plant Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America.
authors: Harvey C
authors: HC
authors: Hoch
authors: Department of Plant Pathology and Plant Microbe Biology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York, United States of America.
authors: Thomas J
authors: TJ
authors: Burr
authors: Department of Biology, Hobart and William Smith Colleges Geneva, New York, United States of America.
authors: Patricia
authors: P
authors: Mowery
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D018441:Biofilms; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000378:metabolism; D005110:Extracellular Space / Q000201:enzymology / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D009154:Mutation; D010935:Plant Diseases / Q000382:microbiology*; D011108:Polymers / Q000378:metabolism; D054730:Protein Interaction Domains and Motifs / Q000235:genetics*; D016415:Sequence Alignment; D014774:Virulence / Q000235:genetics; D044167:Xylella / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity
chemical_list: D001426:Bacterial Proteins; D011108:Polymers; C062025:bis(3',5')-cyclic diguanylic acid; D006152:Cyclic GMP