Soybean Cbl-Interacting Protein Kinase 2 Regulates ROS Homeostasis in Response to Salt Stress

Salt stress is a major environmental stimulus that severely restricts crop yield. Calcineurin B-like proteins-interacting protein kinases (CIPKs) are found to regulate antioxidant system to alleviate abiotic stress. However, the biological functions of CIPKs in soybean adaption to salt stress remain largely unclear. Here, we characterized the role of GmCIPK2 in soybean tolerance to salt stress. GmCIPK2 expression was enhanced by both salt stress and oxidative stress . GmCIPK2- overexpression Arabidopsis and soybean hairy roots displayed improved salt tolerance, whereas GmCIPK2 -RNA interference hairy roots exhibited enhanced salt sensitivity. Furthermore, GmCIPK2 promoted the expression of salt- and antioxidant-related genes after salt stress treatment. Moreover, we found that GmCIPK2 functions importantly in alleviating salt-induced oxidative damage. Besides, GmCIPK2 physially interacts with the calcium sensor GmCBL4 on the plasma membrane. GmCBL4 was identified as a positively regulator in alleviting salt-induced ROS. Overall, this study contributes to elucidating the CBL-CIPK signaling mediated mechanism in soybean salt stress response