Identification of genes for lignin peroxidases and manganese peroxidases in ectomycorrhizal fungi

Genes for ligninolytic enzymes, normally associated with white-rot fungi, a re shown to be widespread in a broad taxonomic range of ectomycorrhizal (EC M) fungi. ECM fungi were screened for lignin peroxidase (LiP) and manganese peroxidas e (MnP) genes by PCR using primers specific for known isozymes in the white -rot fungus Phanerochaete chrysosporium, with DNA sequencing used to confir m the identity of the amplified fragments. Genes for LiPs were detected in ECM fungi representing the orders Agaricale s, Aphyllophorales, Boletales, Cantharellales, Hymenochaetales, Scleroderma tales, Stereales and Thelephorales. MnP genes were detected in only Cortina rius rotundisporus and three ECM Stereales taxa. The presence of genes for decomposer activities supports putative evolution ary relationships between ECM and saprotrophic fungi. Expression of the lig nolytic genes may facilitate ECM fungal access to nutrients associated with dead plant material in soil and potentially a supplementary carbon supply. Strict functional boundaries between ECM and decomposer fungi may be less clear-cut than previously thought.