Plant PI-PLC signaling in stress and development

Phosphoinositide-specific phospholipase C (PI-PLC) signaling is involved in various plant stress and developmental responses. Though several aspects of this lipid signaling pathway are conserved within animals and plants, clear differences have also emerged. While animal PLC signaling is characterized by the hydrolysis of PIP₂ and production of IP₃ and DAG as second messengers to activate Ca²⁺ and PKC signaling, plant PI-PLCs seem to predominantly use PIP as substrate and convert IP₂ and DAG into inositolpolyphosphates and phosphatidic acid (PA) as plant second messengers. Sequencing of multiple plant genomes confirmed that plant PLC signaling evolved differently from animals, lacking homologs of the IP₃ gated-Ca²⁺ channel, PKC and TRP channels, and with PLC enzymes resembling the PLCζ subfamily, which lacks the conserved PH domain that binds PIP₂. With emerging tools in plant molecular biology, data analyses, and advanced imaging, plant PLC signaling is ready to gain momentum.