title: Characterization of a CuZn superoxide dismutase gene in the arbuscular mycorrhizal fungus Glomus intraradices.
abstract: To gain further insights into the mechanisms of redox homeostasis in arbuscular mycorrhizal fungi, we characterized a Glomus intraradices gene (GintSOD1) showing high similarity to previously described genes encoding CuZn superoxide dismutases (SODs). The GintSOD1 gene consists of an open reading frame of 471 bp, predicted to encode a protein of 157 amino acids with an estimated molecular mass of 16.3 kDa. Functional complementation assays in a CuZnSOD-defective yeast mutant showed that GintSOD1 protects the yeast cells from oxygen toxicity and that it, therefore, encodes a protein that scavenges reactive oxygen species (ROS). GintSOD1 transcripts differentially accumulate during the fungal life cycle, reaching the highest expression levels in the intraradical mycelium. GintSOD1 expression is induced by the well known ROS-inducing agents paraquat and copper, and also by fenpropimorph, a sterol biosynthesis inhibitor (SBI) fungicide. These results suggest that GintSOD1 is involved in the detoxification of ROS generated from metabolic processes and by external agents. In particular, our data indicate that the antifungal effects of fenpropimorph might not be only due to the interference with sterol metabolism but also to the perturbation of other biological processes and that ROS production and scavenging systems are involved in the response to SBI fungicides.
authors.affiliation: Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Granada, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: González-Guerrero
authors.forename: Elodie
authors.initials: E
authors.lastname: Oger
authors.forename: Karim
authors.initials: K
authors.lastname: Benabdellah
authors.forename: Concepción
authors.initials: C
authors.lastname: Azcón-Aguilar
authors.forename: Luisa
authors.initials: L
authors.lastname: Lanfranco
authors.forename: Nuria
authors.initials: N
authors.lastname: Ferrol
mesh_terms: D000595:Amino Acid Sequence; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D055137:Glomeromycota / Q000201:enzymology*; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D013482:Superoxide Dismutase / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase