Establishment of an -Mediated Transformation System for .

(Berk.) is a complex is formed by larvae and . Infestation by , interaction with host larvae, and fruiting body development are three crucial processes affecting the formation of . However, research on the molecular mechanism of formation has been hindered by the lack of effective genetic transformation protocols. Therefore, -mediated transformation (ATMT) was adopted to genetically transform two strains and optimize the transformation conditions. The results revealed that the most suitable strain for transformation was AGL1, and that the surfactant Triton X-100 could also induce ATMT, although less effectively than acetosyringone (AS). In addition, the endogenous promoters of genes had a stronger ability to drive the expression of the target gene than did the exogenous promoter. The optimal transformation conditions were as follows: AS and hygromycin B concentrations of 100 μM and 50 μg/mL, respectively; OD of 0.4; cocultivation at 18 °C for 24 h; and used within three passages. The results lay a foundation for the functional study of key regulatory genes involved in the formation of .