CPTF1, a CREB-like transcription factor, is involved in the oxidative stress response in the phytopathogen Claviceps purpurea and modulates ROS level in its host Secale cereale.
CPTF1, a transcription factor with significant homology to ATF/CREB bZIP factors, was identified during an expressed sequence tag (EST) analysis of in planta-expressed genes of the phytopathogen Claviceps purpurea. Using a gene-replacement approach, deletion mutants of cptf1 were created. Expression studies in axenic culture showed that the H2O2-inducible gene cpcat1 (encoding a secreted catalase) had a reduced basal expression level and no longer responded to oxidative stress in the delta cptf1 mutant. Biochemical analyses indicated that CPTF1 is a general regulator of catalase activity. Delta cptf1 mutants showed significantly reduced virulence on rye. Electron microscopical in situ localization revealed significant amounts of H2O2 in delta cptf1-infected rye epidermal tissues, indicating that the plant tissue displayed an oxidative burst-like reaction, an event not detected in wild-type infections. These data indicate that CPTF1 is involved not only in oxidative stress response in the fungus but also in modulation of the plant's defense reactions.
Nathues
Eva
E
Institut für Botanik, Westfälische Wilhelms-Universität, Schlossgarten 3, D-48149 Münster, Germany.
Joshi
Suchitra
S
Tenberge
Klaus B
KB
von den Driesch
Marcell
M
Oeser
Birgitt
B
Bäumer
Nicole
N
Mihlan
Martina
M
Tudzynski
Paul
P
D000595:Amino Acid Sequence; D001483:Base Sequence; D002374:Catalase / Q000378:metabolism; D002967:Claviceps / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*; D004271:DNA, Fungal / Q000235:genetics; D020224:Expressed Sequence Tags; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015870:Gene Expression; D005800:Genes, Fungal; D006861:Hydrogen Peroxide / Q000378:metabolism; D008854:Microscopy, Electron; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation; D018384:Oxidative Stress; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology; D012434:Secale / Q000378:metabolism* / Q000382:microbiology*; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014774:Virulence / Q000235:genetics / Q000502:physiology
D004271:DNA, Fungal; D005656:Fungal Proteins; D014157:Transcription Factors; D006861:Hydrogen Peroxide; D002374:Catalase