Genetic transformation of a mycorrhizal fungus

✍ Scribed by Victoria Barrett; Robert K. Dixon; Paul A. Lemke

• Book ID: 104650879
• Publisher: Springer
• Year: 1990
• Tongue: English
• Weight: 724 KB
• Volume: 33
• Category: Article
• ISSN: 1432-0614
• DOI: 10.1007/bf00164528

✦ Synopsis

Protoplasts of the ectomycorrhizal fungus, Laccaria laccata, were transformed at frequencies of 5-50 transformants/lxg DNA. Transformation was based on positive selection for resistance to hygromycin B (HmB) using the Escherichia coli aminocyclitol phosphotransferase (aph) gene bracketed by an Aspergillus nidulans glyceraldehyde-3-phosphate dehydrogenase (gpd) promoter and the transcription terminator region of the A. nidulans tryptophan synthetase (trpC) gene. Southern blot hybridization revealed that HmB-resistant transformants of L. laccata have integrated vector sequences involving one or more recombination events. These results provide the first evidence for genetic transformation of a mycorrhizal fungus and further indicate the ability of promoter and termination signals of ascomycetous origin to function in a taxonomically unrelated basidiomycete. The potential to improve ectomycorrhizal symbiosis through transgenic manipulation of the fungal component can now be realized, provided specific genes beneficial to this symbiosis can be identified.