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Xlr1 is involved in the transcriptional control of the pentose catabolic pathway, but not hemi-cellulolytic enzymes in Magnaporthe oryzae
- 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.
- Subjects :
- [SDV.SA]Life Sciences [q-bio]/Agricultural sciences
Transcription, Genetic
Pentoses
Mutant
Pentose phosphate pathway
Biology
Microbiology
Fungal Proteins
03 medical and health sciences
chemistry.chemical_compound
Gene Expression Regulation, Fungal
Gene expression
Arabinoxylan
Pentose catabolism
Genetics
Transcriptional regulation
Gene
ComputingMilieux_MISCELLANEOUS
[SDV.MP.MYC]Life Sciences [q-bio]/Microbiology and Parasitology/Mycology
030304 developmental biology
chemistry.chemical_classification
0303 health sciences
Xylose
030306 microbiology
Wild type
food and beverages
Oryza
Magnaporthe oryzae
Arabinose
Magnaporthe
Phosphotransferases (Alcohol Group Acceptor)
Hemicellulose degradation
Enzyme
Biochemistry
chemistry
Xylans
XlnR
Xylanase regulator
Metabolic Networks and Pathways
Subjects
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