Regulation of Plant Immune Signaling by Calcium-Dependent Protein Kinases.

Activation of Ca signaling is a universal response to stress that allows cells to quickly respond to environmental cues. Fluctuations in cytosolic Ca are decoded in plants by Ca-sensing proteins such as Ca-dependent protein kinases (CDPKs). The perception of microbes results in an influx of Ca that activates numerous CDPKs responsible for propagating immune signals required for resistance against disease-causing pathogens. This review describes our current understanding of CDPK activation and regulation, and provides a comprehensive overview of CDPK-mediated immune signaling through interaction with various substrates.