Agrobacterium tumefaciens mediated transformation of Agaricus bisporus

Agrobacterium tumefaciens is known to transfer parts of its tumor-inducing plasmid to filamentous fungi including Agaricus bisporus. We have used this transformation system to transform germinating basidiospores of A. bisporus. Analysis of hygromycin B-resistant clones showed that the T-DNA integrated at random sites and in multiple copies into the host genome. Furthermore we have been able to show that the integrated T-DNA is mitotically and meiotically stable. The data indicate that T-DNA transfer is an efficient system to transform the basidiomycete A. bisporus. We have tested whether it is possible to use the A. tumefaciens system to transform vegetative mycelium of a commercial A. bisporus strain. Our preliminary data suggest that T-DNA transfer could be used to directly transform commercial lines of A. bisporus or their constituent homokaryons.