Abstract:The sequences of the polyphenol oxidase(PPO) gene family were searched from potato genome and were subject to bioinformatics and expression analysis. The results showed that a total of 12 PPO genes, StuPPO1, StuPPO2, StuPPO3, …, StuPPO12 with exception of StuPPO9 localized on chromosome 2, were sorted out and all of them located in the 276 kb range of chromosome 8. Further analysis of the PPO protein sequences with 3 typical structural domains (Tyrosinase, PPO1_DWL, PPO1_KFDV) showed that the similarity of StuPPO1, StuPPO2, StuPPO3, StuPPO4 and StuPPO6 protein sequences was more than 80%, and most of the StuPPO proteins are in chloroplasts. The analysis of cis-acting elements of the promoters showed that StuPPO1, StuPPO2, StuPPO3, StuPPO6, StuPPO8 and StuPPO9 have elements responsive to MeJA; StuPPO1, StuPPO3, StuPPO4, StuPPO6, StuPPO7, StuPPO8, StuPPO9 have element responsive to ABA; StuPPO2, StuPPO4, StuPPO8, StuPPO9 have elements responsive to IAA; A few PPO genes have elements responsive to SA, GA and low temperature. The results of gene expression analysis showed that the expression patterns of different PPO genes of potato were significantly different. StuPPO1, StuPPO2 and StuPPO3 were expressed in the tissues of potato tuber, root, stolon, stem, petiole, young leaves, middle leaves and old leaves; StuPPO4 is only expressed in the tissues of tuber, root, stolon and stem; StuPPO6, StuPPO7, StuPPO8 and StuPPO9 were not expressed in any tissues tested. In addition, the expression of the same gene varied greatly in different tissues of potato.