TALE1 from Xanthomonas axonopodis pv. manihotis acts as a transcriptional activator in plant cells and is important for pathogenicity in cassava plants. (4th September 2012)

• Record Type: Journal Article
• Authors: Castiblanco, Luisa F.; Gil, Juliana; Rojas, Alejandro; Osorio, Daniela; Gutiérrez, Sonia; Muñoz‐Bodnar, Alejandra; Perez‐Quintero, Alvaro L.; Koebnik, Ralf; Szurek, Boris; López, Camilo; Restrepo, Silvia; Verdier, Valérie; Bernal, Adriana J.
• Is Part Of: Molecular plant pathology. Volume 14:Number 1(2013:Jan.)
• Page Start: 84
• Page End: 95
• Publication Date: 2012-09-04
• Subjects: Plant diseases -- Molecular aspects -- Periodicals; Plant-pathogen relationships -- Molecular aspects -- Periodicals; 571.936
• DOI: 10.1111/j.1364-3703.2012.00830.x
• Languages: English
• ISSNs: 1464-6722

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>Many plant‐pathogenic bacteria suppress pathogen‐associated molecular pattern (PAMP)‐triggered immunity by injecting effector proteins into the host cytoplasm during infection through the type III secretion system (TTSS). This type III secretome plays an important role in bacterial pathogenicity in susceptible hosts. <italic>Xanthomonas axonopodis</italic> pv. <italic>manihotis</italic> (<italic>Xam</italic>), the causal agent of cassava bacterial blight, injects several effector proteins into the host cell, including TALE1<italic><sub>Xam</sub></italic>. This protein is a member of the Transcriptional Activator‐Like effector (TALE) protein family, formerly known as the AvrBs3/PthA family. TALE1<italic><sub>Xam</sub></italic> has 13.5 tandem repeats of 34 amino acids each, as well as two nuclear localization signals and an acidic activation domain at the C‐terminus. In this work, we demonstrate the importance of TALE1<italic><sub>Xam</sub></italic> in the pathogenicity of <italic>Xam</italic>. We use versions of the gene that lack different domains in the protein in structure–function studies to show that the eukaryotic domains at the 3′ end are critical for pathogenicity. In addition, we demonstrate that, similar to the characterized TALE proteins from other <italic>Xanthomonas</italic> species, TALE1<italic><sub>Xam</sub></italic> acts as a transcriptional activator in plant cells. This is the first report of the identification of a TALE in <italic>Xam</italic>, and contributes to our understanding of the pathogenicity mechanisms employed by this bacterium to colonize and cause disease in cassava.</p> </abstract>