Skip to Main content Skip to Navigation
Journal articles

Effect of Clay Mineralogy on Iron Bioavailability and Rhizosphere Transcription of 2,4-Diacetylphloroglucinol Biosynthetic Genes in Biocontrol Pseudomonas protegens

Abstract : Pseudomonas strains producing 2,4-diacetylphloroglucinol (DAPG) can protect plants from soil-borne phytopathogens and are considered the primarily reason for suppressiveness of morainic Swiss soils to Thielaviopsis basicola-mediated black root-rot disease of tobacco, even though they also occur nearby in conducive sandstone soils. The underlying molecular mechanism(s) accounting for this discrepancy are not understood. In this study, we assessed the hypothesis that the presence of iron-rich vermiculite clay (dominant in suppressive soils) instead of illite (dominant in neighboring conducive soils) translates into higher levels of iron bioavailability and transcription of Pseudomonas DAPG synthetic genes in the tobacco rhizosphere. Rhizosphere monitoring of reporter gene systems pvd-inaZ and phlA-gfp in Pseudomonas protegens respectively indicated that the level of iron bioavailability and the number of cells expressing phl genes (DAPG synthesis) were higher in vermiculitic than in illitic artificial soils. This was in accordance with the effect of iron on phlA-gfp expression in vitro, and indeed iron addition to the illitic soil increased the number of cells expressing phlA-gfp. Similar findings were made in presence of the pathogen T. basicola. Altogether, results substantiate the hypothesis that iron-releasing minerals may confer disease suppressiveness by modulating iron bioavailability in the rhizosphere and expression of biocontrol-relevant genes in antagonistic P. protegens.
Document type :
Journal articles
Complete list of metadatas

https://hal-univ-lyon1.archives-ouvertes.fr/hal-02522202
Contributor : Depot 1 Lyon 1 <>
Submitted on : Friday, March 27, 2020 - 5:58:06 PM
Last modification on : Tuesday, July 7, 2020 - 5:36:02 PM

Links full text

Identifiers

Collections

Citation

Juliana Almario, Claire Prigent-Combaret, Daniel Muller, Yvan Moënne-Loccoz. Effect of Clay Mineralogy on Iron Bioavailability and Rhizosphere Transcription of 2,4-Diacetylphloroglucinol Biosynthetic Genes in Biocontrol Pseudomonas protegens. Molecular Plant-Microbe Interactions, American Phytopathological Society, 2013, 26 (5), pp.566-574. ⟨10.1094/MPMI-11-12-0274-R⟩. ⟨hal-02522202⟩

Share

Metrics

Record views

157