Objective To investigate the response mechanism of Hemiptelea davidii leaves under salt stress at the transcriptome level and screen for salt tolerance genes.

Methods Based on seven different H. davidii cuttings, transcriptome sequencing and analysis were performed on leaves treated with 0, 100, 150, and 200 mmol·L⁻¹ NaCl solution for 15 days.

Results (1) The screening results of core differentially expressed genes（DEGs） in seven clones showed that except for the DW1, which had slightly more upregulated genes than downregulated genes, all other clones had more downregulated genes than upregulated genes. Moreover, when treated with 200 mmol·L⁻¹ salt solution, each strain had the highest number of DEGS and the strongest response to salt stress. GO enrichment analysis showed that functional genes such as cell wall, had strong responses to salt stress. KEGG enrichment analysis showed that metabolic pathways such as hormone signal transduction, played important roles in the response of 7 clones to salt stress. (2) The four comparative combinations of stronger salt tolerant clones DJ1 and DJ3 and weak salt tolerant clones DW1 and DY1 had a total of 1406 DEGs, including 393 upregulated genes and 996 downregulated genes. Among them, the abscisic acid regulatory factor protein phosphatase 2C (PP2C) genes AHG1, ABI2, ethylene receptor genes ERS1, ETR2, and cyclic nucleotide gated channel genes CNGC10 and CNGC15 might be related to the strong salt tolerance of DJ1 and DJ3.

Conclusion Salt stress causes the response of functional genes and metabolic pathways in H. davidii. Six significantly DEGs will be served as candidate salt tolerant genes. This study provides a theoretical reference for revealing the transcriptome characteristics of H. davidii in response to salt stress and screening salt tolerant genes, laying a foundation for further research and application of H. davidii germplasm resources.