About this Research Topic
In plants, efficient immune responses against microbial infection depend on the ability to rapidly couple pathogen recognition to downstream signaling responses. In this context, plant immunity requires highly dynamic responses that involve multiple organelles during the recognition and signaling events associated to defense. Nuclear dynamics plays a critical role in plant immunity based to the growing number of reports revealing that nuclear localization of pathogen effectors, plant disease resistance proteins, and key plant components, including transcription factors and regulators, are essential for immunity.
Following their delivery into plant cells, a significant number of effector proteins from different pathogenic microorganisms, including viruses, oomycetes, fungi, nematodes, and bacteria, are targeted to the nucleus by co-opting the host nuclear import machinery. This suggests that effectors may manipulate host transcription or directly target essential host nuclear components for the benefit of the pathogen. Indeed, pathogen-induced transcriptional regulation in host cells plays a crucial role in the establishment of plant defense and associated plant cell death responses. Along these lines, it has been estimated that about 25% of Arabidopsis genes are transcriptionally regulated in response to pathogen infection and a significant number of transcription factors are involved in the defense gene regulation. Moreover, spatial restriction of defense regulators by the nuclear envelope as well as their stimulus-induced nuclear translocation provide an important mechanism for defense regulation, as their level of nuclear accumulation determines the magnitude of the defense response. In addition, nuclear translocation of effectors may also affect subcellular localization of their cognate resistance proteins in a process that is essential for plant immunity. Finally, mutations in plant cellular factors involved in the transport of macromolecules through the nuclear envelope compromise plant resistance signaling, underlining the importance of nucleocytoplasmic trafficking during plant innate immunity. Together, these findings situate the nucleus at the forefront of the mutual recognition between plants and pathogens.
In this Research Topic, we aim to provide an open-access update on the current knowledge about the importance of nuclear components – both from the “microbial side” and from the “plant side”- and nuclear dynamics during the establishment of plant immune responses. We will collect Original Research and Review papers on the topic, but also other article types, such as Methods, Commentaries and Opinions are welcome.