A maize stress-responsive Di19 transcription factor, ZmDi19-1, confers enhanced tolerance to salt in transgenic Arabidopsis.

KEY MESSAGE: ZmDi19-1 can be induced by various abiotic stresses and enhance the salt tolerance of transgenic Arabidopsis thaliana. Drought-induced protein 19 (Di19) is an essential zinc finger family member that plays vital roles in regulating multiple stress responses. Here, the Di19 family gene in maize (Zea mays) ZmDi19-1 was characterized. We determined that ZmDi19-1 is constitutively expressed in root, stem, leaf and other maize tissues under normal conditions. In addition, ZmDi19-1 expression was induced by PEG and NaCl stresses. The subcellular localization revealed that ZmDi19-1 is a nuclear membrane protein. In yeast cells, ZmDi19-1 displayed transcriptional activity and could bind to the TACA(A/G)T sequence, which was corroborated using the dual luciferase reporter assay system. The overexpression of ZmDi19-1 in Arabidopsis thaliana enhanced the plants' tolerance to salt stress. Compared with wild-type, the Arabidopsis ZmDi19-1-overexpressing lines had higher relative water and proline contents, and lower malondialdehyde contents, in leaves under salt-stress conditions. The transcriptome analysis revealed 1414 upregulated and 776 downregulated genes, and an RNA-seq analysis identified some differentially expressed genes, which may be downstream of ZmDi19-1, involved in salt-stress responses. The data demonstrated that ZmDi19-1 responds to salt stress and may impact the expression of stress-related genes in Arabidopsis.