Related Experiment Video
Updated: Aug 18, 2026

Imaging Spatial Reorganization of a MAPK Signaling Pathway Using the Tobacco Transient Expression System
Published on: March 20, 2016
SIPK signaling controls multiple components of harpin-induced cell death in tobacco
Marcus A Samuel1, Hardy Hall, Magdalena Krzymowska
1Biotechnology Laboratory, University of British Columbia, Wesbrook Bldg. Rm 237, 6174 University Blvd, Vancouver, BC V6T 1Z3, Canada.
Abstract:
Harpin from Pseudomonas syringae pv. phaseolicola (HrpZ) elicits a rapid cell death response in tobacco plants. Multiple signaling components, including mitogen-activated protein kinase (MAPK), reactive oxygen species (ROS) and salicylic acid (SA), have been reported to be involved in this cell death process, but the interaction between these molecules is poorly understood. Here we show through utilizing plants manipulated in SIPK expression levels that lack of SIPK results in increased sensitivity to harpin with concomitant accumulation of higher levels of ROS. Conversely, SIPK-overexpressing plants show reduced sensitivity to harpin relative to wild-type plants, and display reduced ROS accumulation. Harpin-induced cell death was found to be conditional on the ability of the plant to accumulate SA, whereas harpin induction of MAPK activation and ROS accumulation are not. However, harpin-induced ROS accumulation is required for activation of SIPK and wound-induced protein kinase. Transcriptional profiling revealed that suppression of SIPK signaling also affects early expression of a range of pathogen- and stress-responsive genes during harpin challenge.
Related Concept Videos
Interactions Between Signaling Pathways
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Cell Signaling in Plants
The JAK-STAT Signaling Pathway
Hedgehog Signaling Pathway
Hedgehog Signaling Pathway
MAPK Signaling Cascades

