The Bacterial Effector HopX1 Targets JAZ Transcriptional Repressors to Activate Jasmonate Signaling and Promote Infection in Arabidopsis
Selena Gimenez-Ibanez,Marta Boter,Gemma Fernández-Barbero,Andrea Chini,John P. Rathjen,Roberto Solano +5 more
Reads0
Chats0
TLDR
A bacterial effector protein, HopX1, targets host plant JAZ transcriptional repressors for degradation to activate the jasmonate pathway, thereby promoting bacterial pathogenesis by suppressing host defense responses.Abstract:
Pathogenicity of Pseudomonas syringae is dependent on a type III secretion system, which secretes a suite of virulence effector proteins into the host cytoplasm, and the production of a number of toxins such as coronatine (COR), which is a mimic of the plant hormone jasmonate-isoleuce (JA-Ile). Inside the plant cell, effectors target host molecules to subvert the host cell physiology and disrupt defenses. However, despite the fact that elucidating effector action is essential to understanding bacterial pathogenesis, the molecular function and host targets of the vast majority of effectors remain largely unknown. Here, we found that effector HopX1 from Pseudomonas syringae pv. tabaci (Pta) 11528, a strain that does not produce COR, interacts with and promotes the degradation of JAZ proteins, a key family of JA-repressors. We show that hopX1 encodes a cysteine protease, activity that is required for degradation of JAZs by HopX1. HopX1 associates with JAZ proteins through its central ZIM domain and degradation occurs in a COI1-independent manner. Moreover, ectopic expression of HopX1 in Arabidopsis induces the expression of JA-dependent genes, represses salicylic acid (SA)-induced markers, and complements the growth of a COR-deficient P. syringae pv. tomato (Pto) DC3000 strain during natural bacterial infections. Furthermore, HopX1 promoted susceptibility when delivered by the natural type III secretion system, to a similar extent as the addition of COR, and this effect was dependent on its catalytic activity. Altogether, our results indicate that JAZ proteins are direct targets of bacterial effectors to promote activation of JA-induced defenses and susceptibility in Arabidopsis. HopX1 illustrates a paradigm of an alternative evolutionary solution to COR with similar physiological outcome.read more
Citations
More filters
Journal ArticleDOI
Regulation of pattern recognition receptor signalling in plants.
Daniel Couto,Cyril Zipfel +1 more
TL;DR: The mechanisms that fine-tune immune signalling to maintain immune homeostasis are described and how the innate ability of plant cells to monitor the integrity of key immune components can lead to autoimmune phenotypes following genetic or pathogen-induced perturbations of these components are discussed.
Journal ArticleDOI
Fungal Effectors and Plant Susceptibility
Libera Lo Presti,Daniel Lanver,Gabriel Schweizer,Shigeyuki Tanaka,Liang Liang,Marie Tollot,Alga Zuccaro,Stefanie Reissmann,Regine Kahmann +8 more
TL;DR: This review describes the effector repertoires of 84 plant-colonizing fungi and focuses on the mechanisms that allow these fungal effectors to promote virulence or compatibility, discuss common plant nodes that are targeted by effectors, and provide recent insights into effector evolution.
Journal ArticleDOI
Pseudomonas syringae: what it takes to be a pathogen.
TL;DR: Pseudomonas syringae may serve as an excellent model to understand virulence and also of how pathogenic microorganisms integrate environmental conditions and plant microbiota to become ecologically robust and diverse pathogens of the plant kingdom.
Journal ArticleDOI
Intervention of Phytohormone Pathways by Pathogen Effectors
Kemal Kazan,Rebecca Lyons +1 more
TL;DR: An improved understanding of phytohormone intervention strategies employed by pests and pathogens during their interactions with plants will ultimately lead to the development of new crop protection strategies.
Journal ArticleDOI
Plant-Pathogen Effectors: Cellular Probes Interfering with Plant Defenses in Spatial and Temporal Manners.
TL;DR: This review covers recent advances in the field of effector biology, focusing on conserved cellular processes targeted by effectors from diverse pathogens.
References
More filters
Journal ArticleDOI
Copper enzymes in isolated chloroplasts. polyphenoloxidase in beta vulgaris
TL;DR: Evidence that a copper enzyme, polyphenoloxidase (otherwise known as tyrosinase or catecholase), is localized in the chloroplasts of spinach beet (chard), Beta vu?garis is presented.
Journal ArticleDOI
Floral dip: a simplified method for Agrobacterium-mediated transformation of Arabidopsis thaliana
Steven J. Clough,Andrew F. Bent +1 more
TL;DR: The modified method should facilitate high-throughput transformation of Arabidopsis for efforts such as T-DNA gene tagging, positional cloning, or attempts at targeted gene replacement.
Journal ArticleDOI
The plant immune system
TL;DR: A detailed understanding of plant immune function will underpin crop improvement for food, fibre and biofuels production and provide extraordinary insights into molecular recognition, cell biology and evolution across biological kingdoms.
Journal ArticleDOI
JAZ repressor proteins are targets of the SCF COI1 complex during jasmonate signalling
Bryan Thines,Leron Katsir,Maeli Melotto,Yajie Niu,Ajin Mandaokar,Guanghui Liu,Kinya Nomura,Sheng Yang He,Gregg A. Howe,John Browse +9 more
TL;DR: The results suggest a model in which jasmonate ligands promote the binding of the SCFCOI1 ubiquitin ligase to and subsequent degradation of the JAZ1 repressor protein, and implicate theSCFCOi1–JAZ1 protein complex as a site of perception of the plant hormone JA–Ile.
Journal ArticleDOI
The JAZ family of repressors is the missing link in jasmonate signalling
Andrea Chini,Sandra Fonseca,Guillermo Fernández,Bruce Adie,José-Manuel Chico,Oscar Lorenzo,Gloria García-Casado,Irene López-Vidriero,Francisca María Lozano,María Rosa Ponce,José Luis Micol,Roberto Solano +11 more
TL;DR: The identification of JASMONATE-INSENSITIVE 3 (JAI3) and a family of related proteins named JAZ (jasmonate ZIM-domain), in Arabidopsis thaliana and the existence of a regulatory feed-back loop involving MYC2 and JAZ proteins, which provides a mechanistic explanation for the pulsed response to jasmonate and the subsequent desensitization of the cell.