The present invention relates to a novel method for increasing the resistance of a plant, in particular of a Solanaceae, preferably of potato and tomato, to plant pathogens of the phylum Oomyceta comprising increasing the activity of the polypeptide of the present invention. The invention further relates to polynucleotides and vectors comprising these polynucleotides. The invention furthermore relates to corresponding vectors, cells, transgenic plants and transgenic propagation material derived from them, methods to produce them and to their use for the production of foodstuffs, feeding stuffs, seed, pharmaceuticals or fine chemicals.