Objective This study aimed to explore the downstream response genes of Dendrobium catenatum Lindl. DcCIPK24, and provided guidance for studying the molecular regulatory pathway of DcCIPK24 to improve salt tolerance.

Method The DcCIPK24 transgenic Arabidopsis thaliana and wild type plants under 200 mmol/L NaCl treatment and normal conditions were used for RNA-seq on the illumina NovaSeq 6000 sequencing platform. The enrichment pathway of differentially expressed genes (DEGs) was analyzed, and their expression patterns were verified by quantitative real-time PCR.

Result A total of 96 DEGs were identified from transgenic A. thaliana and wild type plants under salt stress. GO annotation analysis showed that 96 DEGs were mainly enriched in molecular function pathways. KEGG enrichment analysis found that DEGs enriched in amino sugar and nucleotide sugar metabolism, plant MAPK signaling pathway and glycerolipid metabolism. The DEGs including four upregulated genes (AtGPAT5, AtSIRK, AtMEE25, and AtUGE5) and four downregulated genes (AtAMT1-2, AtATTI3, AtCYP71A25, and AtLHCB4.3) were selected for qRT-PCR validation. The results showed that the trends of 8 DEGs' expression were basically consistent with the RNA-seq data.

Conclusion DcCIPK24 responded to salt tolerance mainly through amino sugar and nucleotide sugar metabolism, plant MAPK signaling pathway, and glycerolipid metabolism.