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Xlr1 is involved in the transcriptional control of the pentose catabolic pathway, but not hemi-cellulolytic enzymes in Magnaporthe oryzae

Authors :
Julie Vallet
Sylvia Klaubauf
Evy Battaglia
Ronald P. de Vries
Cécile Ribot
Marc-Henri Lebrun
Microbiology and Kluyver Centre for Genomics of Industrial Fermentation
Utrecht University [Utrecht]
CBS KNAW Fungal Biodivers Ctr
Unité de Recherche Vigne et Vins de Champagne Stress et Environnement - EA 4707 (URVVC)
Université de Reims Champagne-Ardenne (URCA)-SFR Condorcet
Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS)-Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS)
Biologie et Génétique des Interactions Plante-Parasite (UMR BGPI)
Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)
BIOlogie et GEstion des Risques en agriculture (BIOGER)
AgroParisTech-Institut National de la Recherche Agronomique (INRA)
Physiologie des plantes et des champignons lors de l'infection
Bayer Cropscience-Centre National de la Recherche Scientifique (CNRS)
Institut National de la Recherche Agronomique (INRA)-AgroParisTech
Technologiestichting STW UGC 07063
Univ Utrecht, CBS KNAW Fungal Biodivers Ctr & Fungal Mol Physio, Fungal Physiol, NL-3508 TC Utrecht, Netherlands
Partenaires INRAE
Univ Claude Bernard Lyon, Inst Natl Sci Appl Bayer CropSci Joint Lab UMR524, CNRS, Bayer CropSci, F-69263 Lyon 9, France
Université Paris Diderot - Paris 7 (UPD7)
Centre National de la Recherche Scientifique (CNRS)-Bayer Cropscience
Source :
Fungal Genetics and Biology, Fungal Genetics and Biology, Elsevier, 2013, 57, pp.76-84. ⟨10.1016/j.fgb.2013.06.005⟩, Fungal Genetics and Biology, 57, 76-84. Academic Press
Publication Year :
2013
Publisher :
Elsevier BV, 2013.

Abstract

International audience; Magnaporthe oryzae is a fungal plant pathogen of many grasses including rice. Since arabinoxylan is one of the major components of the plant cell wall of grasses, M. oryzae is likely to degrade this polysaccharide for supporting its growth in infected leaves. D-Xylose is released from arabinoxylan by fungal depolymerising enzymes and catabolized through the pentose pathway. The expression of genes involved in these pathways is under control of the transcriptional activator XlnR/Xlr1, conserved among filamentous ascomycetes. In this study, we identified M. oryzae genes involved in the pentose catabolic pathway (PCP) and their function during infection, including the XlnR homolog, XLR1, through the phenotypic analysis of targeted null mutants. Growth of the Delta xlr1 strain was reduced on D-xylose and xylan, but unaffected on L-arabinose and arabinan. A strong reduction of PCP gene expression was observed in the Delta xlr1 strain on D-xylose and L-arabinose. However, there was no significant difference in xylanolytic and cellulolytic enzyme activities between the Delta xlr1 mutant and the reference strain. These data demonstrate that XLR1 encodes the transcriptional activator of the PCP in M. oryzae, but does not appear to play a role in the regulation of the (hemi-) cellulolytic system in this fungus. This indicates only partial similarity in function between Xlr1 and A. niger XlnR. The deletion mutant of D-xylulose kinase encoding gene (XKI1) is clearly unable to grow on either D-xylose or L-arabinose and showed reduced growth on xylitol, L-arabitol and xylan. Delta xki1 displayed an interesting molecular phenotype as it over-expressed other PCP genes as well as genes encoding (hemi-) cellulolytic enzymes. However, neither Delta xlr1 nor Delta xki1 showed significant differences in their pathogeny on rice and barley compared to the wild type, suggesting that p-xylose catabolism is not required for fungal growth in infected leaves. (C) 2013 Elsevier Inc. All rights reserved.

Details

ISSN :
10871845 and 10960937
Volume :
57
Database :
OpenAIRE
Journal :
Fungal Genetics and Biology
Accession number :
edsair.doi.dedup.....bb4441cb9ace7b86f509d6e346f86970
Full Text :
https://doi.org/10.1016/j.fgb.2013.06.005