Abstract
Exposed to unfavorable environments such as pathogen attack, plants quickly establish the defense system. The MAP Kinase (MAPK) cascade plays a critical role in the signal transduction for cellular responses. In tobacco plants, WIPK is one of the representative MAPKs, and well characterized. However, the downstream factor(s) of WIPK has not so far been identified, leaving the whole signaling system rather obscure.
Using the yeast two hybrid screening system, we obtained one particular protein, which specifically interacts with WIPK, and designated as NtWIF. In order to examine the biological function, we generated NtWIF over-expressed transgenic tobacco plants, which were found to produce a high level of salicylic acid. Consequently, transcripts of PR-related genes were up-regulated. Results suggested that NtWIF is involved in regulation of salicylic acid-responsive genes. Further screening of affected genes by micro-array is currently under the progress.
