Estudio de la interacción tomate-Pseudomonas syringae mediante transcriptómica y genómica funcional

ROSLI, HERNÁN GUILLERMO

Encuentro; Resiliencia en plantas: Desafíos globales; 2017

Universidad de Talca, Chile

Background: Microbe-associated molecular patterns (MAMPs) such as those present in bacterial flagellin are powerful inducers of the innate immune response in plants. Successful pathogens deliver virulence proteins, termed effectors, into the plant cell where they can interfere with the immune response and promote disease. Engineering of the plant immune system to enhance disease resistance requires a thorough understanding of its components necessitating a comprehensive approach to gene discovery.Results: We describe a screen using RNA-Seq and virus-induced gene silencing (VIGS) to identify tomato genes whose expression is enhanced by the flagellin MAMP flgII-28 but reduced by activities of the Pseudomonas syringae pv. tomato (Pst) type III effectors AvrPto and AvrPtoB. Gene ontology (GO) terms for this category of flagellin-induced, repressed by effectors (FIRE) genes showed it to be enriched for genes encoding certain subfamilies of protein kinases and transcription factors. At least twenty-five of the FIRE genes have been implicated previously in plant immunity. Thirty-three of the 92 protein kinase-encoding FIRE genes were subjected to VIGS and their involvement in pattern-triggered immunity was tested with a simple leaf-based assay. Silencing of one FIRE gene, which encodes a cell wall-associated kinase (SlWAK1), compromised the plant immune response resulting in increased growth of Pst and enhanced disease symptoms.Conclusions: Our transcriptomic approach allowed the identification of FIRE genes that represent a ?pathogen-defined? core set of immune-related genes. The analysis of this set of candidate genes led to the discovery of a cell wall-associated kinase that participates in plant defense. The FIRE genes will be useful for further elucidation of the plant immune system.