The Pseudomonas type III effector HopQ1 activates cytokinin signaling and interferes with plant innate immunity. Issue 2 (11th October 2013)

• Record Type: Journal Article
• Authors: Hann, Dagmar R.; Domínguez‐Ferreras, Ana; Motyka, Vaclav; Dobrev, Petre I.; Schornack, Sebastian; Jehle, Anna; Felix, Georg; Chinchilla, Delphine; Rathjen, John P.; Boller, Thomas
• Is Part Of: New phytologist. Volume 201:Issue 2(2014)
• Page Start: 585
• Page End: 598
• Publication Date: 2013-10-11
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/nph.12544
• Languages: English
• ISSNs: 0028-646X

Abstract

<abstract abstract-type="main" id="nph12544-abs-0001"> <title>Summary</title> <p> <list id="nph12544-list-0001" list-type="bullet"> <list-item> <p>We characterized the molecular function of the <italic>Pseudomonas syringae</italic> pv. <italic>tomato </italic>DC3000 (<italic>Pto</italic>) effector HopQ1.</p> </list-item> <list-item> <p> <italic>In silico</italic> studies suggest that HopQ1 might possess nucleoside hydrolase activity based on the presence of a characteristic aspartate motif. Transgenic <italic>Arabidopsis</italic> lines expressing <italic>HopQ1</italic> or <italic>HopQ1</italic> aspartate mutant variants were characterized with respect to flagellin triggered immunity, phenotype and changes in phytohormone content by high‐performance liquid chromatography‐MS (HPLC‐MS).</p> </list-item> <list-item> <p>We found that HopQ1, but not its aspartate mutants, suppressed all tested immunity marker assays. Suppression of immunity was the result of a lack of the flagellin receptor FLS2, whose gene expression was abolished by HopQ1 in a promoter‐dependent manner. Furthermore, HopQ1 induced cytokinin signaling in <italic>Arabidopsis</italic> and the elevation in cytokinin signaling appears to be responsible for the attenuation of <italic>FLS2</italic> expression.</p> </list-item> <list-item> <p>We conclude that HopQ1 can activate cytokinin signaling and that moderate activation of cytokinin signaling leads to suppression of <italic>FLS2</italic> accumulation and thus defense signaling.</p> </list-item> </list> </p> </abstract>