title: The plant host Brassica napus induces in the pathogen Verticillium longisporum the expression of functional catalase peroxidase which is required for the late phase of disease.
abstract: The devastating soilborne fungal pathogen Verticillium longisporum is host specific to members of the family Brassicaceae, including oilseed rape (Brassica napus) as the economically most important crop. The fungus infects through the roots and causes stunting and early senescence of susceptible host plants and a marked decrease in crop yield. We show here that V. longisporum reacts to the presence of B. napus xylem sap with the production of six distinct upregulated and eight downregulated proteins visualized by two-dimensional gel electrophoresis. Identification of 10 proteins by mass spectrometry revealed that all upregulated proteins are involved in oxidative stress response. The V. longisporum catalase peroxidase (VlCPEA) was the most upregulated protein and is encoded by two isogenes, VlcpeA-1 and VlcpeA-2. Both genes are 98% identical, corroborating the diploid or "amphihaploid" status of the fungus. Knock downs of both VlcpeA genes reduced protein expression by 80% and resulted in sensitivity against reactive oxygen species. Whereas saprophytic growth and the initial phase of the plant infection were phenotypically unaffected, the mutants were not able to perform the late phases of disease. We propose that the catalase peroxidase plays a role in protecting the fungus from the oxidative stress generated by the host plant at an advanced phase of the disease.
authors: Institut für Mikrobiologie und Genetik, Georg-August Universität, 37077 Göttingen, Germany. gbraus@gwdg.de
authors: Seema
authors: S
authors: Singh
authors: Susanna A
authors: SA
authors: Braus-Stromeyer
authors: Christian
authors: C
authors: Timpner
authors: Oliver
authors: O
authors: Valerius
authors: Andreas
authors: A
authors: von Tiedemann
authors: Petr
authors: P
authors: Karlovsky
authors: Christine
authors: C
authors: Druebert
authors: Andrea
authors: A
authors: Polle
authors: Gerhard H
authors: GH
authors: Braus
mesh_terms: D029688:Brassica napus / Q000382:microbiology* / Q000502:physiology*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal / Q000502:physiology*; D020868:Gene Silencing; D006861:Hydrogen Peroxide; D008969:Molecular Sequence Data; D010544:Peroxidases / Q000235:genetics / Q000378:metabolism*; D010935:Plant Diseases / Q000382:microbiology; D015854:Up-Regulation; D020172:Verticillium / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D006861:Hydrogen Peroxide; D010544:Peroxidases