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Mediation of pathogen resistance by exudation of antimicrobials from roots

A Retraction to this article was published on 02 March 2011


Most plant species are resistant to most potential pathogens. It is not known why most plant–microbe interactions do not lead to disease, although recent work indicates that this basic disease resistance is multi-factorial1,2. Here we show that the exudation of root-derived antimicrobial metabolites by Arabidopsis thaliana confers tissue-specific resistance to a wide range of bacterial pathogens. However, a Pseudomonas syringae strain that is both at least partly resistant to these compounds and capable of blocking their synthesis/exudation is able to infect the roots and cause disease. We also show that the ability of this P. syringae strain to block antimicrobial exudation is dependent on the type III secretory system.

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Figure 1: Pathogenicity of various P. syringae pathovars against A. thaliana.
Figure 2: Activated charcoal enhances virulence of non-host pathogens.
Figure 3: Kinetics of accumulation of a representative antimicrobial compound (butanoic acid) in Arabidopsis root exudates.

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We thank W. Songnuan and J. Dangl for critical reading of the manuscript, and E. Wortman-Wunder for editing suggestions. This work was supported by the Colorado State University Agricultural Experiment Station (J.M.V.) and by NIH and NSF grants to F.M.A. J.M.V. is a NSF-CAREER Faculty Fellow.

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Correspondence to Frederick M. Ausubel or Jorge M. Vivanco.

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Supplementary information

Supplementary Methods

This file contains additional details of methods and materials used in the study. (DOC 86 kb)

Supplementary Figures S1-S8

This file contains Supplementary Figures S1-S8 (PPT 34891 kb)

Supplementary Legends

Legends to accompany the above Supplementary Figures. (DOC 53 kb)

Supplementary Table S1

Ten secondary metabolites detected in the root exudates of A. thaliana depicted as marker compounds. (PPT 170 kb)

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Bais, H., Prithiviraj, B., Jha, A. et al. Mediation of pathogen resistance by exudation of antimicrobials from roots. Nature 434, 217–221 (2005).

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