Establishment of a PEG-mediated protoplast transformation system for the orchid mycorrhizal fungus Mycena purpureofusca.

An efficient PEG-mediated protoplast transformation system for Mycena purpureofusca was established, achieving a transformation frequency of 4.3% with stable hygromycin-resistant isolates.

• Why it matters: Understanding orchid-fungal symbiosis is limited by the lack of reliable genetic tools for M. purpureofusca, hindering research and strain improvement efforts in this important ecological and economic context.
• What they did: Researchers optimized key parameters such as fungal age, osmotic stabilizer, lywallzyme concentration, digestion temperature, and time, using the pCAMBIA1303 vector to develop the transformation system.
• The result: The system yielded 8.90 × 10^6 protoplasts/mL with a regeneration efficiency of 3.54%, enabling stable genetic modification and facilitating future functional studies in orchid-associated fungi.