Abstract: The exchanges of components between the cytoplasm and the nucleus exist in both the plant cells and and animal cells. The macromolecules involved in the nuclear membrane transport are conservative in most eukaryotes. These nuclei components mutations impair the signal transduction of plant defense. It indicates that nucleocytoplasmic exchange plays an important role in plants innate immunity. The  spatial isolation of defense regulators by the nuclear envelope and stimulus induced nuclear translocation are of great significance to the defense-associated gene regulation in plants. Lots of effectors from various pathogens are targeted to the cell nucleus of host plants. Additionly, the frequent tran-port of important host factors, like R proteins, immunity components, transcription factors and transcriptional regulators between the cytoplasm and the nucleus, and their amounts in the nuclear determine the defense response of the host plants. All the facts show the importance of the nucleus in the interaction between plants and pathogens. This paper makes a summary of recent discoveries that show the significant role of nucleus played in the mutual recognition between pathogens and plants.

Key words: nucleus, nucleocytoplasmic trafficking, defense response signal transport, plant immune response