Heterologous Expression of Chrysanthemum TCP Transcription Factor CmTCP13 Enhances Salinity Tolerance in .

Plant-specific TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) proteins play critical roles in plant development and stress responses; however, their functions in chrysanthemum () have not been well-studied. In this study, we isolated and characterized the chrysanthemum TCP transcription factor family gene , a homolog of . This gene encoded a protein harboring a conserved basic helix-loop-helix motif, and its expression was induced by salinity stress in chrysanthemum plants. Subcellular localization experiments showed that CmTCP13 localized in the nucleus. Sequence analysis revealed the presence of multiple stress- and hormone-responsive -elements in the promoter region of . The heterologous expression of in plants enhanced their tolerance to salinity stress. Under salinity stress, transgenic plants exhibited enhanced germination, root length, seedling growth, and chlorophyll content and reduced relative electrical conductivity compared with those exhibited by wild-type (WT) plants. Moreover, the expression levels of stress-related genes, including , , , , and , were upregulated in transgenic plants than in WT plants under salt stress. Taken together, our results demonstrate that is a critical regulator of salt stress tolerance in plants.