Objective To lay a molecular basis for functional verification experiment and genetic breeding of tree salinity tolerance, the genetic mechanisms was explored, and salt-related genes were identified for Sonneratia apetala Buch.-Ham.

Method In this study, the root tissues were collected from a 1-year-old S. apetala treated with 500 mmol•L⁻¹ NaCl for 0 (control group) and 10 d (treatment group). Then transcriptome sequencing and bioinformatics analysis was performed based on the three-generation full-length transcriptome dataset of S. apetala.

Result (1) Compared with the control group, 14401 genes were differentially expressed after salt treatment, of which 7153 were up-regulated and 7248 were down-regulated. (2) GO analysis found that a total of 11068 differential genes were annotated in 47 GO items. (3) For KEGG enrichment analysis, a total of 6189 differential expression genes were enriched to 134 pathways, of which 14 were significantly enriched (P-value <0.01, Q-value <0.05). (4) Further functional annotation analysis of the differentially expressed genes revealed a total of 89 genes was potential salt-related candidate genes. Among these, 24, 22, 19, 10 and 14 genes encoded enzymes or functional proteins referred to antioxidation, osmotic adjustment substances, plant hormones, protein kinase and transcription factors, respectively.

Conclusion Genes relating to active oxygen scavenging, osmotic regulation, plant hormones, protein kinases and transcription factors participate in the regulation of salt stress adaptation in S. apetala.