The Interaction of CaM7 and CNGC14 Regulates Root Hair Growth in Arabidopsis

The study explored the interaction between calmodulin 7 (CaM7) and the cyclic nucleotide gated channel 14 (CNGC14) in regulating root hair growth in Arabidopsis. It was found that CaM7 directly interacts with CNGC14, specifically through the third EF-hand domain of CaM7 and the cytosolic C-terminal domain of CNGC14. This interaction was shown to inhibit CNGC14-mediated calcium influx, indicating that CaM7 negatively regulates calcium signaling. Overexpression of CaM7 resulted in a short root hair phenotype similar to that of a cngc14 mutant, which was not affected by external calcium concentrations. The study concluded that the CaM7-CNGC14 interaction is a novel mechanism controlling polar growth in root hairs by modulating tip-focused calcium signals.