Genetic transformation of the fungus Gliocladium sp. mediated by Agrobacterium tumefaciens

OBJECTIVE: To construct a transformation system in Gliocladium sp. 6.102, a Cordyceps-colonizing fungus producing a variety of epipolythiodioxopiperazine (ETP) compounds with drug potentials. METHODS: Agrobacterium tumefaciens-mediated transformation (ATMT) was used to transform Gliocladium sp. 6.102. The factors of bacterial cell concentration, co-cultivation time, pH and acetosyringone concentration were optimized. RESULTS; A total of 50 -100 transformants per 10(6) fungal conidia was obtained via the optimal ATMT method. The genes encoding hygromycin B phosphotase and enhanced green fluorescent protein (EGFP) were transferred into Gliocladium sp. by the optimal ATMT method. The marker genes were successfully expressed and stably maintained in the transgenic fungus. CONCLUSION: A transformation system was established for Gliocladium sp. 6.102 and this system may be useful to identify ETP biosynthetic genes in Gliocladium.