Taphrina deformans is a biotrophic pathogen that causes peach leaf curl, a worldwide disease that is potentially devastating to both yield and tree longevity.It has a dimorphic life cycle with a hyphal stage and a yeast form.The yeast phase resulting from budding of ascospores is saprophytic and can be cultured on artificial media.The hyphal form is associated with plant infection and obligate biotrophic.Although the underlying mechanism is not clear, dimorphic switching in this homothallic fungus is assumed to be related to sexual reproduction and pathogenesis.As a plant pathogen in Taphrinomycotina,T.deformans has great potentials for being used to study mechanisms of fungal-plant interactions and evolution of effectors and dimorphism.In this study, we tested with different transformation protocols and developed an electroporation transformation procedure with blastospores.The transforming vectors contained the GFP reporter gene either fused to Hi-histone gene of T.deformans or under its promoter control.The transformation efficiency was compared with different forms of transforming DNAs.The resulting transformants were used to examine nuclear behaviors during blastospore germination and dimorphic switching.Invasive hyphae growing in peach tissues also were examined with leaves inoculated with GFP-labelled transformants.A model depictive of different fungal development and infection stages of T.deformans will be presented.