Abstract: The hooks and inflorescences of Uncaria rhynchophylla, two homologous organs at different developmental stages, including hook buds and inflorescence buds at the initial stage, as well as formed hooks and young inflorescences, served as materials for transcriptome sequencing. Differentially expressed genes (DEGs) in the hook developmental process (hook buds vs. hooks) and the inflorescence developmental process (inflorescence buds vs. young inflorescences) were screened, and the transcriptional patterns of the two developmental processes were compared through cluster analysis. The results showed that a total of 97 060 unigenes were obtained from RNA-seq data assembly. In total, 1 637 and 6 179 DEGs were identified in the hook and inflorescence developmental processes, respectively. Among these, genes with significant differential expression (|log₂（FC）| ≥ 2) exhibited distinct differences in GO functional clustering and KEGG pathway enrichment. There were 524 common DEGs shared by the two developmental processes; enrichment analysis indicated that both hook and inflorescence development involved responses to endogenous signals and external environmental stimuli. Further screening of these common DEGs identified 52 transcription factor (TF) genes, which were clustered into 7 categories based on their expression patterns. The majority of these genes were involved in regulating reproductive development, suggesting that the transcriptional regulatory network they constituted was closely related to the divergence in developmental fate between hooks and inflorescences.

Key words: Uncaria rhynchophylla, hooks, inflorescences, developmental stages, comparative transcriptome analysis