The Clubroot Pathogen (Plasmodiophora brassicae) Influences Auxin Signaling to Regulate Auxin Homeostasis in Arabidopsis

Plants

Linda Jahn¹  Stefanie Mucha¹  Sabine Bergmann¹  Cornelia Horn¹  Paul Staswick³  Bianka Steffens²  Johannes Siemens¹ 

[1] Institut für Botanik, Technische Universität Dresden, 01062 Dresden, Germany; E-Mails:;Botanisches Institut, Universität Kiel, Am Botanischen Garten 5, 24118 Kiel, Germany; E-Mail:;Department of Agronomy and Horticulture, University of Nebraska, 379 Keim, Lincoln, NE 68521 USA; E-Mail:

关键词: ABP1;    Arabidopsis thaliana;    auxin homeostasis;    auxin receptors;    clubroot disease;    GH3 proteins;    Plasmodiophora brassicae;    potassium channel inhibitors;    tetraethylammonium;    TIR1;   

DOI  :  10.3390/plants2040726

来源: mdpi

【 摘 要 】

The clubroot disease, caused by the obligate biotrophic protist Plasmodiophora brassicae, affects cruciferous crops worldwide. It is characterized by root swellings as symptoms, which are dependent on the alteration of auxin and cytokinin metabolism. Here, we describe that two different classes of auxin receptors, the TIR family and the auxin binding protein 1 (ABP1) in Arabidopsis thaliana are transcriptionally upregulated upon gall formation. Mutations in the TIR family resulted in more susceptible reactions to the root pathogen. As target genes for the different pathways we have investigated the transcriptional regulation of selected transcriptional repressors (Aux/IAA) and transcription factors (ARF). As the TIR pathway controls auxin homeostasis via the upregulation of some auxin conjugate synthetases (GH3), the expression of selected GH3 genes was also investigated, showing in most cases upregulation. A double gh3 mutant showed also slightly higher susceptibility to P. brassicae infection, while all tested single mutants did not show any alteration in the clubroot phenotype. As targets for the ABP1-induced cell elongation the effect of potassium channel blockers on clubroot formation was investigated. Treatment with tetraethylammonium (TEA) resulted in less severe clubroot symptoms. This research provides evidence for the involvement of two auxin signaling pathways in Arabidopsis needed for the establishment of the root galls by P. brassicae.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.