Iron deficiency affects plant defence responses and confers resistance to Dickeya dadantii and Botrytis cinerea

Authors

  • NAM PHUONG KIEU,

    1. Department of Plant Biotechnology and Biotransformation, Faculty of Biology, University of Science Ho Chi Minh City, 227 Nguyen Van Cu, District 5, Ho Chi Minh City, Vietnam
    2. Laboratoire des Interactions Plantes-Pathogènes UMR217 INRA/AgroParisTech/UPMC, 16 rue Claude Bernard 75231, Cedex 05 Paris, France
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    • Present address: Laboratory of Phytopathology, Faculty of Bioscience Engineering, Ghent University, Coupure Links, 653, B-9000 Ghent, Belgium.

  • AUDE AZNAR,

    1. Laboratoire des Interactions Plantes-Pathogènes UMR217 INRA/AgroParisTech/UPMC, 16 rue Claude Bernard 75231, Cedex 05 Paris, France
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  • DIEGO SEGOND,

    1. Laboratoire des Interactions Plantes-Pathogènes UMR217 INRA/AgroParisTech/UPMC, 16 rue Claude Bernard 75231, Cedex 05 Paris, France
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    • INRA UMR-1319 Institut Micalis, Génétique Microbienne et Environnement Domaine de La Minière, 78285 Guyancourt Cedex, France.

  • MARTINE RIGAULT,

    1. Laboratoire des Interactions Plantes-Pathogènes UMR217 INRA/AgroParisTech/UPMC, 16 rue Claude Bernard 75231, Cedex 05 Paris, France
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  • ELIZABETH SIMOND-CÔTE,

    1. Laboratoire des Interactions Plantes-Pathogènes UMR217 INRA/AgroParisTech/UPMC, 16 rue Claude Bernard 75231, Cedex 05 Paris, France
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  • CAROLINE KUNZ,

    1. Laboratoire des Interactions Plantes-Pathogènes UMR217 INRA/AgroParisTech/UPMC, 16 rue Claude Bernard 75231, Cedex 05 Paris, France
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  • MARIE-CHRISTINE SOULIE,

    1. Laboratoire des Interactions Plantes-Pathogènes UMR217 INRA/AgroParisTech/UPMC, 16 rue Claude Bernard 75231, Cedex 05 Paris, France
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  • DOMINIQUE EXPERT,

    1. Laboratoire des Interactions Plantes-Pathogènes UMR217 INRA/AgroParisTech/UPMC, 16 rue Claude Bernard 75231, Cedex 05 Paris, France
    2. CNRS Laboratoire des Plantes-Pathogènes F-75005 Paris, France
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  • ALIA DELLAGI

    Corresponding author
    1. Laboratoire des Interactions Plantes-Pathogènes UMR217 INRA/AgroParisTech/UPMC, 16 rue Claude Bernard 75231, Cedex 05 Paris, France
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Email: dellagi@agroparistech.fr

SUMMARY

Iron is an essential element for most living organisms, and pathogens are likely to compete with their hosts for the acquisition of this element. The bacterial plant pathogen Dickeya dadantii has been shown to require its siderophore-mediated iron uptake system for systemic disease progression on several host plants, including Arabidopsis thaliana. In this study, we investigated the effect of the iron status of Arabidopsis on the severity of disease caused by D. dadantii. We showed that symptom severity, bacterial fitness and the expression of bacterial pectate lyase-encoding genes were reduced in iron-deficient plants. Reduced symptoms correlated with enhanced expression of the salicylic acid defence plant marker gene PR1. However, levels of the ferritin coding transcript AtFER1, callose deposition and production of reactive oxygen species were reduced in iron-deficient infected plants, ruling out the involvement of these defences in the limitation of disease caused by D. dadantii. Disease reduction in iron-starved plants was also observed with the necrotrophic fungus Botrytis cinerea. Our data demonstrate that the plant nutritional iron status can control the outcome of an infection by acting on both the pathogen's virulence and the host's defence. In addition, iron nutrition strongly affects the disease caused by two soft rot-causing plant pathogens with a large host range. Thus, it may be of interest to take into account the plant iron status when there is a need to control disease without compromising crop quality and yield in economically important plant species.

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