Superoxide dismutases in the entomopathogenic fungus Metarhizium anisopliae

Control of gene expression is a key subject in Molecular Biology. Superoxide dismutases are essential enzymes to protect living organisms against toxicity of radicals generated by the metabolism and represent an ideal system to study gene regulation. Filamentous fungi are extensively used as model eukaryotic systems and some representatives are important microorganisms in the biological control of insects in agriculture. Metarhizium anisopliae is employed at a commercial scale to control insects in sugar-cane plantations and pastures in Brazil and is currently the best studied entomopathogenic fungus. It possesses three SOD activities, CuZnSOD, MnSOD and Fe SOD. The iron enzyme is found in fungi for the first time. A gene coding for SOD was cloned by PCR amplification, partially sequenced and is under characterization. Transformation systems are developed but rendering poor efficiencies. Homologous genes have been isolated and should increase transformation yields. (AU)