XopD SUMO Protease Affects Host Transcription, Promotes Pathogen Growth, and Delays Symptom Development in Xanthomonas-Infected Tomato Leaves

• Published in: The Plant cell Vol. 20; no. 7; pp. 1915 - 1929
• Main Authors: Kim, Jung-Gun, Taylor, Kyle W, Hotson, Andrew, Keegan, Mark, Schmelz, Eric A, Mudgett, Mary Beth
• Format: Journal Article
• Language: English
• Published: United States American Society of Plant Biologists 01.07.2008
• Subjects: bacterial proteins; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacterial Proteins - physiology; chlorophyll; Chlorophyll - metabolism; chlorosis; Deoxyribonucleic acid; DNA; DNA-binding proteins; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; DNA-Binding Proteins - physiology; gene expression regulation; Gene Expression Regulation, Plant; Genes; host plants; Host-Pathogen Interactions; host-pathogen relationships; Hypochromic anemia; Immunoblotting; Infections; jasmonic acid; Leaves; Lycopersicon esculentum - genetics; Lycopersicon esculentum - metabolism; Lycopersicon esculentum - microbiology; Messenger RNA; Molecular Sequence Data; Mutagenesis, Site-Directed; Necrosis; pathogenesis; Pathogens; Phenotypes; Plant cells; Plant Diseases - genetics; Plant Diseases - microbiology; Plant Leaves - genetics; Plant Leaves - metabolism; Plant Leaves - microbiology; plant pathogenic bacteria; Reverse Transcriptase Polymerase Chain Reaction; salicylic acid; Salicylic Acid - metabolism; signs and symptoms (plants); Solanum lycopersicum; Tomatoes; transcription (genetics); Transcription, Genetic; Xanthomonas - genetics; Xanthomonas - metabolism; Xanthomonas - physiology; Xanthomonas campestris pv. vesicatoria
• ISSN: 1040-4651; 1532-298X; 1532-298X
• DOI: 10.1105/tpc.108.058529

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.