The Ca2+/OsCaM1-OsSARD1-OsDREB1A/1B/1H module orchestrates chilling tolerance signaling in rice

In plants, Ca2+/calmodulins (CaMs) play a central role in mediating the transcriptional regulation under low temperature stress. However, how OsSARD1, a Ca2+/CaM-regulated CBP60 family protein, modulates the cold stress response remains largely unknown in rice. Here, we identified the new role of Ca2+/OsCaM1-OsSARD1 module in chilling tolerance signaling in rice. Our transgenic experiments showed that cold-highly induced genes OsCaM1-1 and OsSARD1 positively regulated cold tolerance in rice seedlings. The in vitro peptide binding, pull-down, Co-IP and BiFC assays showed that OsCaM1 interacts specifically with OsSARD1 in a Ca2+-dependent manner.