## 4 Discussion
Sankey diagram visualization (Figure 5) revealed that _Phoebe_ seeds were associated with \"floral,\" \"fruity,\" and \"sweet\" descriptors, whereas leaves displayed dominant \"green,\" \"herbal,\" and \"spicy\" attributes. These trends mirror structural class differences, as ionones, esters, and certain aldehydes commonly contribute to floral/fruity notes, while GLVs (green leaf volatiles) and terpenes drive green/herbal aromas [21; 26; 31]. Such divergence in volatile perception likely reflects underlying ecological roles, in which seed volatiles may attract mutualists, while leaf volatiles function primarily in defense. The Venn diagram analysis revealed both conserved and tissue-related volatile metabolites across species. In the species comparison (ZJN1_vs_ZN1 and ZJN2_vs_ZN2), 953 shared metabolites were identified in both seeds and leaves (Figure 6A), likely representing core species-related volatiles driven by genetic regulation. These included mainly terpenoids and norisoprenoids, consistent with patterns reported in other Lauraceae plants [32; 33]. An organ-level comparison (ZN2_vs_ZN1 and ZJN2_vs_ZJN1) identified 899 shared metabolites between species (Figure 6B), indicating conserved tissue-related profiles. Leaf volatiles tended to include GLVs and sesquiterpenes, while seeds were enriched in fruity and floral compounds, reflecting ecological roles such as defense or dispersal [26; 27]. Meanwhile, species- and organ-related subsets highlight the joint influence of tissue function and evolutionary background. These findings provide a basis for chemotaxonomic markers, fragrance-oriented selection, and future gene-metabolite association studies. In addition to species- and tissue-related comparisons, our findings can be contextualized with previous studies on Lauraceae plants and other aromatic trees. For example, _Litesa cubbea_ fruits were reported to be enriched in monoterenes like citral and limonene, whereas _Cinnamounum camphora_ leaves and bark primarily accumulated linalool and camphor-typesesquiterpenes [34; 35]. In contrast, _Phoebe_ seeds in our study were dominated by noriso-prenoids and aldehydes contributing floral and fruity aromas, while the leaves featured GLVs and diverse terpenids linked to green and herbal attributes. These differences may reflect organ- related ecological roles such as seed dispersal or herbivore defense, as well as species-related adaptations to microenvironmental conditions or evolutionary lineage. Mechanistically, such divergence may result from the differential expression of terpene synthase (TPS), cytochrome P450, and acyltransferase genes that modulate downstream volatile diversity in a tissue-preferential manner, as suggested in Lauraceae transcriptome-based studies [29; 30]. However, direct evidence linking gene expression to volatile output in _Phoebe_ is still lacking and requires integrated transcriptomic and enzyme-level validation. As a limitation, our analysis relied solely on semi-quantitative GC-MS metabolomics of volatile extracts from two organs and two species under a single environmental condition. Without dry-weight normalization or water content correction, subtle changes in concentration may reflect physiological variation. In addition, although KEGG pathway enrichment provided useful biological context, it was based only on metabolite identity and relative abundance. Therefore, claims of pathway upregulation should be interpreted with caution. Beyond their ecological and biological relevance, the distinct volatile profiles observed in _Phoebe_ seeds and leaves offer practical implications for the fragrance, essential oil, and wood product industries. For example, the enrichment of fruity and floral norisoprenoids in seeds suggests their potential as sources of natural aromatic additives or fragrance extracts. Meanwhile, the accumulation of green and herbal GLVs and terpenids in leaves aligns with odor profiles desired in air fresheners or insect-repellent formulations.