Genome-wide identification, transcriptional profiling, and miRNA-binding site analysis of the LBD gene family in the camphor tree

<i>Cinnamomum camphora</i> (Lauraceae), an evergreen arborescent species endemic to East Asian ecosystems, is ecologically and economically prized for three cardinal attributes: decay-resistant xylem, aesthetic canopy architecture, and pharmacologically active terpenoid emissions. The plant-specific Lateral Organ Boundaries Domain (LBD) transcription factors mediate phylogenetically conserved developmental pathways governing lateral organogenesis and secondary metabolism across embryophytes. Despite multiple published <i>C. camphora</i> genome assemblies, functional characterization of LBD transcription factors in this species remains limited. We systematically identified 40 <i>LBD</i> genes through whole-genome analysis and characterized their structural features, evolutionary relationships, and expression patterns. Five are intron-free, while seven genes harbor two or more introns each. Detailed annotation of <i>CcLBD</i> promoter regions identified 33 cis-regulatory elements linked to hormone signaling and stress adaptation. Transcriptional dynamics of the 40 <i>CcLBD</i> genes were profiled across seven tissues of the camphor tree using short-read RNA-Seq, revealing that 22 genes were highly expressed in flowers and 12 were predominantly expressed in roots, suggesting potential roles in reproductive organ development and root formation in <i>C. camphora</i>. Phylogenetic analysis classified all CcLBD proteins into two clades, each harboring a conserved lateral organ boundaries (LOB) domain. Integrative omics analyses (small RNA-seq and degradome data) further implicated miR408 and miR2950c in post-transcriptional regulation of <i>CcLBD5</i> via mRNA cleavage. These results establish a framework for the functional dissection of LBD-mediated developmental and stress-response pathways in <i>C. camphora</i>.