, Volume 46, Issue 4, pp 215-222

Cytosolic Ca2+ pulses and protein kinase activation in the signal transduction pathways leading to the plant oxidative burst

Abstract

The oxidative burst, the rapid production of O2- and H2O2 by plant cells in response to pathogens and Stressors, is a critical step in plant disease resistance and is controlled by several different elicitor-initiated signaling pathways. While different defense elicitors appear to activate disparate initial steps in signaling the oxidative burst, all of the elicitors tested thus far appear to stimulate pathways that converge on the same three core signaling intermediates: 1) the Ca2+-independent activation of a mitogen-activated protein kinase (MAPK) family member, 2) the influx of Ca2+ into the cytosol, deriving most critically from an internal compartment, and 3) the Ca2+-dependent activation of additional protein kinases including a second MAPK homologue and possibly calcium dependent protein kinases (CDPKs). Data from several recent reports are summarized to place these signaling events into a complete and updated model of signaling to the plant oxidative burst.