Plasma membrane-associated calcium signaling modulates zinc homeostasis in Arabidopsis

Zinc (Zn) is a crucial micronutrient for all organisms, and its deficiency can significantly hamper crop yield and quality. However, the understanding of the regulatory mechanisms involved in plant Zn signal perception and transduction remains limited. In this study, we discovered that the Ca²⁺-CBL1/4/5/8/9-CIPK3/9/23/26-ZIP12 signaling module effectively responds to Zn deficiency and regulates Zn homeostasis in Arabidopsis thaliana. Furthermore, we determined that CIPK3/9/23/26 interact with the Zn transporter ZIP12 and phosphorylate it primarily at Ser185. This phosphorylation event was crucial for the stability of the ZIP12 protein, suggesting that it regulates the function of ZIP12 in Zn transport. Collectively, our findings identify a plasma membrane-associated calcium signaling pathway that regulates Zn homeostasis in Arabidopsis thaliana. This pathway represents a promising target for molecular breeding approaches aimed at developing crops with enhanced tolerance to Zn deficiency.