Ectopic expression of BdCIPK31 confers enhanced low-temperature tolerance in transgenic tobacco plants.

Calcineurin B-like protein (CBL), the Ca2+ sensor, and its interacting protein kinases (CIPKs) play essential roles in plants' response to stress. However, few studies have focused on the functions of CIPKs in low-temperature response. In the present study, BdCIPK31, a cold-responsive CIPK in Brachypodium distachyon, was found to participate in low-temperature response. Ectopic expression of BdCIPK31 conferred cold tolerance in transgenic tobaccos. Further analyses indicated that expression of BdCIPK31 improved ROS detoxication and omsoprotectant biosynthesis in transgenic plants under low-temperature treatment, suggesting that the BdCIPK31 functions positively in plant adaption to the cold-induced oxidative and osmotic stresses. Moreover, BdCIPK31 could upregulate the expressions of some representative stress-related genes under cold stress. In conclusion, these findings suggest that BdCIPK31 functions positively in plant cold response.