Genetic transformation of ectomycorrhizal fungi mediated by Agrobacterium tumefaciens

A technique was developed for transforming the ectomycorrhiza-forming basidiomycetes Suillus bovinus, Hebelonza cylindrosporum, and Paxillits involutus based on Agrobacterium tumefaciens-mediated T-DNA transfer. The selection marker employed was the Shble gene conferring resistance to phleomycin under control of the Schizophyllum commune GPD promoter and terminator. Transformants from all three investigated species were shown by PCR to contain the GPDScP-Shble-GPDScT construct, although the fate of the foreign DNA (integrated vs episomal, single-copy vs multi copy) could not be determined. The mycorrhiza formed between S. bovinus Ble(r) transformants and Pinus sylvestris did not reveal any differences from those formed with untransformed Suillus bovinus.