The ectomycorrhizal basidiomycete Laccaria bicolor releases a secreted β‐1,4 endoglucanase that plays a key role in symbiosis development
- UMR 1136 INRA‐Université de Lorraine ‘Interactions Arbres/Microorganismes’, Laboratoire d'Excellence ARBRE, Centre INRA‐Lorraine 54280 Champenoux France
- INRA, Aix‐Marseille Université, UMR 1163, Biodiversity and Biotechnology of Fungi 13009 Marseille France, CNRS, UMR 7257 &, Architecture et Fonction des Macromolécules Biologiques, Aix‐Marseille Université Marseille France
- INRA, Aix‐Marseille Université, UMR 1163, Biodiversity and Biotechnology of Fungi 13009 Marseille France
- Laboratorio de Micología Molecular Departamento de Ciencia y Tecnología Universidad Nacional de Quilmes and CONICET Bernal Provincia de Buenos Aires Argentina
- CNRS, UMR 7257 &, Architecture et Fonction des Macromolécules Biologiques, Aix‐Marseille Université Marseille France, INRA, USC 1408 AFMB 13288 Marseille France, Department of Biological Sciences King Abdulaziz University Jeddah Saudi Arabia
Summary In ectomycorrhiza, root ingress and colonization of the apoplast by colonizing hyphae is thought to rely mainly on the mechanical force that results from hyphal tip growth, but this could be enhanced by secretion of cell‐wall‐degrading enzymes, which have not yet been identified. The sole cellulose‐binding module ( CBM 1) encoded in the genome of the ectomycorrhizal Laccaria bicolor is linked to a glycoside hydrolase family 5 ( GH 5) endoglucanase, Lb GH 5‐ CBM 1. Here, we characterize Lb GH 5‐ CBM 1 gene expression and the biochemical properties of its protein product. We also immunolocalized Lb GH 5‐ CBM 1 by immunofluorescence confocal microscopy in poplar ectomycorrhiza. We show that Lb GH 5‐ CBM 1 expression is substantially induced in ectomycorrhiza, and RNA i mutants with a decreased Lb GH 5‐ CBM 1 expression have a lower ability to form ectomycorrhiza, suggesting a key role in symbiosis. Recombinant Lb GH 5‐ CBM 1 displays its highest activity towards cellulose and galactomannans, but no activity toward L. bicolor cell walls. In situ localization of Lb GH 5‐ CBM 1 in ectomycorrhiza reveals that the endoglucanase accumulates at the periphery of hyphae forming the Hartig net and the mantle. Our data suggest that the symbiosis‐induced endoglucanase Lb GH 5‐ CBM 1 is an enzymatic effector involved in cell wall remodeling during formation of the Hartig net and is an important determinant for successful symbiotic colonization.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 1432129
- Journal Information:
- New Phytologist, Journal Name: New Phytologist Vol. 220 Journal Issue: 4; ISSN 0028-646X
- Publisher:
- Wiley-BlackwellCopyright Statement
- Country of Publication:
- United Kingdom
- Language:
- English
Web of Science
Similar Records
The genome of Laccaria bicolor provides insights into mycorrhizal symbiosis
The Genome of Laccaria Bi color Provides Insights into Mycorrhizal Symbiosis