Xanthomonas Type III Effector XopD Desumoylates Tomato Transcription Factor SlERF4 to Suppress Ethylene Responses and Promote Pathogen Growth

• Published in: Cell host & microbe 2013-02, Vol.13 (2), p.143-154
• Main Authors: Kim, Jung-Gun, Stork, William, Mudgett, Mary Beth
• Format: Article
• Language: English
• Subjects: Bacterial Proteins - genetics; Bacterial Proteins - immunology; Bacterial Proteins - metabolism; Bacterial Secretion Systems; Disease Susceptibility - immunology; Disease Susceptibility - microbiology; Ethylenes - biosynthesis; Ethylenes - immunology; Genes, Plant; Host-Pathogen Interactions; Lyases - genetics; Lyases - metabolism; Lycopersicon esculentum - enzymology; Lycopersicon esculentum - genetics; Lycopersicon esculentum - immunology; Lycopersicon esculentum - microbiology; Plant Diseases - immunology; Plant Diseases - microbiology; Plant Leaves - microbiology; Plant Proteins - genetics; Plant Proteins - metabolism; Proteasome Endopeptidase Complex - metabolism; Protein Interaction Mapping; Protein Stability; RNA, Messenger - genetics; RNA, Messenger - metabolism; Sumoylation; Transcription Factors - genetics; Transcription Factors - metabolism; Transcription, Genetic; Xanthomonas - growth & development; Xanthomonas - immunology; Xanthomonas - pathogenicity
• ISSN: 1931-3128; 1934-6069
• DOI: 10.1016/j.chom.2013.01.006

XopD, a type III secretion effector from Xanthomonas euvesicatoria (Xcv), the causal agent of bacterial spot of tomato, is required for pathogen growth and delay of host symptom development. XopD carries a C-terminal SUMO protease domain, a host range determining nonspecific DNA-binding domain and two EAR motifs typically found in repressors of stress-induced transcription. The precise target(s) and mechanism(s) of XopD are obscure. We report that XopD directly targets the tomato ethylene responsive transcription factor SlERF4 to suppress ethylene production, which is required for anti-Xcv immunity and symptom development. SlERF4 expression was required for Xcv ΔxopD-induced ethylene production and ethylene-stimulated immunity. XopD colocalized with SlERF4 in subnuclear foci and catalyzed SUMO1 hydrolysis from lysine 53 of SlERF4, causing SlERF4 destabilization. Mutation of lysine 53 prevented SlERF4 sumoylation, decreased SlERF4 levels, and reduced SlERF4 transcription. These data suggest that XopD desumoylates SlERF4 to repress ethylene-induced transcription required for anti-Xcv immunity. ► Xanthomonas effector XopD suppresses ethylene-stimulated immunity late in infection ► XopD interacts with tomato ethylene response factor SlERF4 in subnuclear foci ► XopD desumoylation of SlERF4 at K53 reduces SlERF4 stability and transcription ► Silencing SlERF4 reduces ethylene levels and increases susceptibility to Xcv ΔxopD