Ustilago hordei is a kind of basidiomycete fungi that causes covered smut of barley(Hordeum vulgare L.), which can bring about significant yield loss to global barley production. In this paper, we studied the physiological and infection properties of Ustilago hordei. To establish a gene transformation system of Ustilago hordei, ATMT(Agrobacterium tumefaciens mediated transformation) method was chosen, and the factors might influence transformation efficency were optimized. In addition, how Ustilago hordei m...