Figure 2.

Schema model of SOS pathway regulated by Ca²⁺ under saline shock. Ca²⁺ signaling triggered by salt stress activate SOS3 causes interaction with SOS2. SOS3/SOS2 complex activates SOS1 by direct phosphorylation driven by SOS2 and result in Na⁺ efflux. Alternatively, SOS2 regulates vacuolar channels (CAX and NHX) and balance Na⁺ vacuolar sequestration. CAX: Vacuolar H⁺/Ca²⁺ antiporter, CBL: Calcineurin B-like protein, CIPK: CBL-interacting protein kinase, NHX: Vacuolar located Na⁺/H⁺ antiporters, SOS: Salt overly sensitive, SS: Salt stress. SRR: Sal responsive receptors.