Fig. 7.

A putative mechanistic model of the broad spectrum resistance mediated by Pib. The fungal avirulence factor is recognized by the Pib protein, which triggers kinase-mediated and hormone signaling to transduce the appropriate signal to a suite of downstream transcription factors. The activation of these transcription factors regulates genes encoding products involved in ROS metabolism and various defense-related proteins, leading eventually to the expression of the hypersensitive response. ET ethylene, JA jasmonate, TF transcription factor, ROS reactive oxygen species, HR hypersensitive response