Ilex dabieshanensis is not only an important ornamental plant, but can also be used to produce Kuding tea, owing to its lipid-lowering and anti-inflammatory medicinal properties. The genetic transformation of I. dabieshanensis is currently difficult, which restricts functional gene studies and molecular breeding research on this species. Virus-induced gene silencing (VIGS) is a powerful tool for determining gene functions in plants. The present study reports the first application of VIGS mediated by a tobacco rattle virus (TRV) vector in I. dabieshanensis. We tested the efficiency of the VIGS system to silence Mg-chelatase H subunit (ChlH) gene through agroinfiltration. The agroinfiltrated leaves of I. dabieshanensis exhibited a typical yellow-leaf phenotype of ChlH gene silencing at 21 days post infiltration. Endogenous ChlH expression levels in the leaves of yellow-leaf phenotype plants were all significantly lower than that in the leaves of mock-infected and control plants. Overall, our results indicated that the TRV-based VIGS system can efficiently silence genes in I. dabieshanensis, and this system will contribute to efficient functional genomics research in I. dabieshanensis.

Plant-specific TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) proteins play critical roles in plant development and stress responses; however, their functions in chrysanthemum (Chrysanthemum morifolium) have not been well-studied. In this study, we isolated and characterized the chrysanthemum TCP transcription factor family gene CmTCP13, a homolog of AtTCP13. 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 cis-elements in the promoter region of CmTCP13. The heterologous expression of CmTCP13 in Arabidopsis plants enhanced their tolerance to salinity stress. Under salinity stress, CmTCP13 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 AtSOS3, AtP5CS2, AtRD22, AtRD29A, and AtDREB2A, were upregulated in CmTCP13 transgenic plants than in WT plants under salt stress. Taken together, our results demonstrate that CmTCP13 is a critical regulator of salt stress tolerance in plants.