ABCG1 encodes a member of the plasma membrane-localized ABC (ATP-binding cassette)-half transporter subfamily G, and was identified by using microarray analyses as a candidate gene responsive to the pathogen-associated molecular pattern Pep-13. Further analyses revealed a basal accumulation of ABCG1-transcripts mainly in roots and tuber periderm. The gene is also induced in response to leaf wounding as well as to pathogen infection by P. infestans. Transgenic ABCG-RNAi potato plants display major alterations in root and tuber morphology with partially disorganized cell layers. In addition, microscopic analyses of the tuber periderm and root exodermis of RNAi plants show reduced suberin staining. Metabolite analyses revealed a strong reduction of the major and minor monomers of aliphatic tuber suberin and a hyper-accumulation of putative suberin precursors in the tuber periderm of RNAi plants, suggesting a role of ABCG1 in the modulation of suberinization in the cells of the phellem in the potato tuber periderm.