Fig. 10

MsSOS2-mediated Na⁺ and K⁺ homeostasis in transgenic Arabidopsis. Under salinity, phospholipase D (PLD) hydrolyzes phosphatidylcholine (PC) to generate phosphatidic acid (PA). Salinity also induces intracellular Ca²⁺, which activates AtSOS3 upon binding. Activated AtSOS3 then facilitates MsSOS2 interaction and activation, concurrently with its PA-mediated membrane anchoring. This combined action subsequently activates AtSOS1, ultimately leading to Na⁺ homeostasis. The upper part of the figure, partitioned with thick grey line illustrates that AtCBL10 inhibits AKT1 under control conditions. In response to salinity, PA-bound MsSOS2 interacts with AtCBL10 and inhibits its interaction with AKT1. This allows AKT1 to absorb K⁺, contributing to K⁺ homeostasis. Dashed lines represent a proposed relationship, but not an experimentally verified one. A question mark indicates where direct interaction between the two indicated elements has not been examined.