The present invention concerns a transgenic plant of the species Solanum tuberosum with a resistance to an oomycete of the genus Phytophthora, transgenic parts of such a plant, a method for its manufacture and to a composition for external application to plants. On the one hand, nucleotide sequences in accordance with SEQ ID NOS: 1-43 are provided from Phytophthora in a host plant-induced gene silencing strategy in potato plants; on the other hand, a fungicide for plant treatment is provided.
