title: Oxidative stress response of filamentous fungi induced by hydrogen peroxide and paraquat.
abstract: Although, oxidative stress response, which protects organisms from deleterious effects of reactive oxygen species (ROS), has been extensively studied in pro- and eukaryotes, the information about filamentous fungi is fragmentary. We investigated the effect of two ROS-generating agents (paraquat, PQ, and H2O2) on cellular growth and antioxidant enzyme induction in 12 fungal species. Our results indicate that exposure of fungal spores or mycelia to PQ and H2O2 promoted oxidative stress, as evidenced by remarkable inhibition of spore germination and biomass production; stimulation of cyanide-resistant respiration; accumulation of oxidative modified proteins. Cell responses against both superoxide and peroxide stresses include enhanced expression of superoxide dismutase (SOD) and catalase, however, the extent was different: treatment with PQ increased mainly SOD, whereas exogenous H2O2 led to enhanced catalase. We also found that G6PD has a role in the mechanism of protection against superoxide and peroxide stresses. The activation of antioxidant enzyme defence was blocked by the translation inhibitor, cycloheximide, suggesting that there was de novo enzyme synthesis.
authors.affiliation: Institute of Microbiology, Bulgarian Academy of Sciences, Academician G Bonchev 26, 1113 Sofia, Bulgaria. mariange@microbio.bas.bg
authors.forename: Maria B
authors.initials: MB
authors.lastname: Angelova
authors.forename: Svetlana B
authors.initials: SB
authors.lastname: Pashova
authors.forename: Boryana K
authors.initials: BK
authors.lastname: Spasova
authors.forename: Spassen V
authors.initials: SV
authors.lastname: Vassilev
authors.forename: Lyudmila S
authors.initials: LS
authors.lastname: Slokoska
mesh_terms: D002374:Catalase / Q000378:metabolism*; D005658:Fungi / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D018869:Heat-Shock Response; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress; D010269:Paraquat / Q000494:pharmacology*; D013172:Spores, Fungal / Q000187:drug effects; D013482:Superoxide Dismutase / Q000378:metabolism*
chemical_list: D016877:Oxidants; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase; D010269:Paraquat