Xyr1 regulates xylanase but not cellulase formation in the head blight fungus Fusarium graminearum.
Fusarium graminearum is a plant pathogen that causes severe economical losses by infecting numerous agriculturally important plants and until now most culture plants have only low levels of Fusarium resistance. The plant cell wall can be assumed as the first target that has to be overcome by plant pathogens. Therefore pathogenic organisms are known to produce a complex cocktail of plant cell wall lytic enzymes. Xylanases are besides cellulases the most prominent enzymes secreted by Fusarium during growth on plant cell walls. We identified a putative regulator of xylanase production with high similarity to the Aspergillus niger XlnR and the Trichoderma reesei Xyr1 proteins. Disruptant strains of F. graminearum were heavily impaired in xylose utilization and xylanase production on wheat cell walls. In contrast to other filamentous fungi the lack of this transcriptional activator had no effect on the induction of cellulases.
Brunner
Kurt
K
Vienna University of Technology, Institute of Chemical Engineering, Research Area of Gene Technology and Applied Biotechnology, Getreidemarkt 9, 1060 Vienna, Austria. brunner@mail.zserv.tuwien.ac.at
Lichtenauer
Anton M
AM
Kratochwill
Klaus
K
Delic
Marizela
M
Mach
Robert L
RL
D002480:Cellulase / Q000096:biosynthesis; D043364:Endo-1,4-beta Xylanases / Q000096:biosynthesis*; D004790:Enzyme Induction / Q000502:physiology; D005656:Fungal Proteins / Q000235:genetics / Q000502:physiology*; D005670:Fusarium / Q000201:enzymology* / Q000235:genetics; D016681:Genome, Fungal; D030781:Organisms, Genetically Modified
D005656:Fungal Proteins; D002480:Cellulase; D043364:Endo-1,4-beta Xylanases