# TaCML49-B, a Calmodulin-like Protein, Interacts with TaIQD23 to Positively Regulate Salt Tolerance in Wheat

## TL;DR

This study identifies TaCML49-B, a wheat protein, as a key player in salt tolerance by interacting with TaIQD23, offering new insights into plant stress responses.

## Contribution

The study reveals a novel interaction between TaCML49-B and TaIQD23, showing their role in enhancing salt tolerance in wheat.

## Key findings

- TaCML49-B is upregulated in wheat roots under salt stress and localizes to multiple cellular compartments.
- Overexpression of TaCML49-B in Arabidopsis improves salt tolerance, while its silencing in wheat reduces salt resistance.
- TaCML49-B physically interacts with TaIQD23, suggesting a role in salt stress signaling.

## Abstract

Calcium signaling is essential for coordinating plant responses to diverse stimuli and regulating growth and development. Among calcium sensors, calmodulin (CaM) and CaM-like proteins (CMLs) represent a class that, despite increasing research, remains incompletely characterized in wheat, with many interacting partners and biological functions remaining largely elusive. This study conducted bioinformatics analyses of subgroup II CaM/CMLs, characterizing their phylogenetic relationships, conserved motifs, sequence features, and cis-elements. Expression analysis revealed that TaCML49-B was significantly upregulated in roots under salt stress. Moreover, TaCML49-B was localized to nucleus, cytoplasm, and membrane. Function characterization demonstrated that overexpression of TaCML49-B in Arabidopsis enhanced salt tolerance, whereas the BSMV-VIGS silencing of TaCML49-B reduced salt resistance in wheat. Furthermore, STRING database prediction analysis and bimolecular fluorescence complementation (BiFC) assay confirmed that TaCML49-B can physically interact with TaIQD23, which encodes an IQ67 domain protein, suggesting its potential involvement in the salt stress signaling pathway. Collectively, our findings indicate that TaCML49-B functions as a positive role in wheat salt stress response, thereby providing novel insights into the functions of TaCML genes and calcium signaling in wheat.