CaM4 Functions as a Positive Regulator of the SOS Pathway in Response to Salt Stress

from plant cells. A deficiency in CaM4 further reduced SOS2 kinase activity in scabp8sos3 double mutant plants. Thus, CaM4, together with SOS3 and SCaBP8, coregulate SOS2 kinase activity in Arabidopsis to promote its adaptation to salt stress. Collectively, our results show that CaM4 is a positive regulator of the SOS signalling pathway, which promotes plant salt tolerance.