Abstract: The present invention provides a system in which a recombinant plant expressing a target peptide is orally administered to thereby achieve exertion of the function of the peptide, along with the genetically recombinant plant, and the present invention relates to a carrier system for oral administration of a target peptide by oral administration of a plant (potato) that expresses a target peptide by expressing for example a fused gene obtained by fusing the LRE1 gene coding for the immunogenic peptide LRE1 derived from the Leucocytozoon caulleryi 2nd-generation schizont with a Norwalk virus coat protein gene, along with the relevant genetically recombinant plant, and thus, in the present invention the orally administered target peptide can reach an intended destination (such as the intestinal mucosa) without being decomposed in the digestive tract, so that the function of the target peptide can be induced.