Figure 2
From: Insights into genomics of salt stress response in rice
Overall signaling pathway in rice during salt stress. Salt stress evokes both osmotic and ionic stress. Osmotic stress signaling is transduced via ABA-dependent or ABA-independent pathway. ABA dependent pathway includes mitogen activated protein kinase (MAP Kinase) cascades, calcium-dependent protein kinases (CDPK), receptor-like kinases (RLK), SNF1-related protein kinases (SnRK), transcription factors (OsRAB1, MYC/MYB and OsNAC/SNAC) and micro RNAs. ABA-independent pathway includes transcription factors (OsDREB1 and OsDREB2) and stress related genes (OsPSY1, OsNCEDs). Ionic stress does signaling via Ca2+/PLC pathway and salt overly sensitive (SOS) pathway and Calmodulin (CaM) pathway. Ca2+ is sensed by Ca2+ sensor (OsCBL4) and the sensor activates calcineurin B-like protein kinase (OsCIPK24), which in turns activates Na+/H+ antiporter (OsSOS1), H+/Ca+ antiporter (OsCAX1), vacuolar H+/ATPase, vacuolar Na+/H+ exchangers (OsNHX1) and suppress K+/Na+ symporter (OsHKT1) to maintain ionic homeostasis under salt stress. Ca2+ also activates calmodulin (OsMSR2) which also activates vacuolar Na+/H+ exchanger (OsNHX1). Blue arrow indicates ABA dependent pathway, green arrow shows ABA-independent pathway, violet arrow shows ROS pathway, red arrow shows Ca2+/PLC pathway and orange arrow shows SOS pathway.