Abstract
We demonstrate that XopD, a type III effector from Xanthomonas campestris pathovar vesicatoria (Xcv), suppresses symptom production during the late stages of infection in susceptible tomato (Solanum lycopersicum) leaves. XopD-dependent delay of tissue degeneration correlates with reduced chlorophyll loss, reduced salicylic acid levels, and changes in the mRNA abundance of senescence- and defense-associated genes despite high pathogen titers. Subsequent structure-function analyses led to the discovery that XopD is a DNA binding protein that alters host transcription. XopD contains a putative helix-loop-helix domain required for DNA binding and two conserved ERF-associated amphiphilic motifs required to repress salicylic acid- and jasmonic acid-induced gene transcription in planta. Taken together, these data reveal that XopD is a unique virulence factor in Xcv that alters host transcription, promotes pathogen multiplication, and delays the onset of leaf chlorosis and necrosis.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Bacterial Proteins / genetics
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Bacterial Proteins / metabolism
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Bacterial Proteins / physiology*
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Chlorophyll / metabolism
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DNA-Binding Proteins / genetics
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DNA-Binding Proteins / metabolism
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DNA-Binding Proteins / physiology
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Gene Expression Regulation, Plant
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Host-Pathogen Interactions
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Immunoblotting
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Molecular Sequence Data
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Mutagenesis, Site-Directed
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Plant Diseases / genetics
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Plant Diseases / microbiology
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Plant Leaves / genetics
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Plant Leaves / metabolism
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Plant Leaves / microbiology*
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Reverse Transcriptase Polymerase Chain Reaction
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Salicylic Acid / metabolism
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Solanum lycopersicum / genetics
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Solanum lycopersicum / metabolism
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Solanum lycopersicum / microbiology*
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Transcription, Genetic
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Xanthomonas / genetics
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Xanthomonas / metabolism
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Xanthomonas / physiology*
Substances
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Bacterial Proteins
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DNA-Binding Proteins
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Chlorophyll
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Salicylic Acid
Associated data
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GENBANK/AF043085
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GENBANK/AM039952
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GENBANK/AY600438