The present invention relates to methods of generating or increasing resistance to at least one biotrophic pathogen in a plant or a part of a plant by increasing the protein quantity or function of at least one Bax Inhibitor-1 (BI-1) protein in at least one part of the plant. Moreover, the invention relates to polypeptide sequences and nucleic acid sequences which code for a BI-1 protein, and to expression cassettes, vectors and organisms which comprise such sequences or such a protein.