Abstract
WIPK is a protein kinase from tobacco transcriptionally induced by wounding and activation of the hypersensitive response (HR). A yeast two-hybrid screen for proteins interacting with WIPK led to the identification of a new protein, NtWIF. The C-terminus of NtWIF interacts with WIPK in the yeast two-hybrid system as well as in an in vitro pull-down assay. The N-terminus shows high sequence similarity to the DNA binding domain of ARF transcriptional regulators, and the middle region confers transactivation activity to a luciferase reporter gene. Furthermore, a GFP-NtWIF fusion construct localizes to the nucleus in onion epidermal cells, suggesting a role of NtWIF as a transcription factor.
Transgenic tobacco plants constitutively expressing full-length NtWIF were produced. These plants have a drastically changed expression pattern of wound responsive genes. Our results provide evidence for the involvement of NtWIF in a signal transduction pathway from WIPK to the transcriptional control of wound-responsive genes.
