As a detrimental abiotic stressor, salinity affects plant growth and yield. Domain of unknown function 1644 (DUF1644) is a large plant-specific DUF protein family that is predicted to be involved in abiotic stress responses in plants. However, the biological functions of DUF1644 genes in plants remain largely unexplored, especially in halophytes. Here, we investigated the function of the DUF1644 gene, ZmSIDP1, from the halophyte Zoysia matrella. ZmSIDP1 could enhance the salt tolerance of yeast. Furthermore, the heterologous transformation of the ZmSIDP1 gene in rice demonstrated that transgenic rice plants exhibited better growth under NaCl treatment. The Na