## 1 Introduction  
Volatile organic compounds (VOCs) play crucial roles in plant physiology and ecology, acting as key mediators in plant-environment interactions, defense responses, and inter-organism communication [1, 2]. Beyond their ecological functions, VOCs contribute significantly to the flavor and aroma quality of foods, spices, herbal medicines, and aromatic wood products [3]. The composition and abundance of VOCs are highly species- and organ-related and are influenced by genetic background, tissue type, developmental stage, and environmental factors [4, 5]. Recent advances in plant metabolomics have enabled the large-scale profiling of volatile metabolites, providing new insights into the biochemical diversity and evolutionary significance of plant aroma profiles [6]. Understanding the patterns and mechanisms of VOC accumulation across species and organs is essential for exploring biodiversity, guiding aroma-oriented breeding, and optimizing the use of aromatic and medicinal plants. The genus _Phoebe_ (Lauraceae) includes over 200 species worldwide, many of which are valued for their ecological roles, fragrant wood, and horticultural appeal [7]. Among them, _P. zhennan_ and _P. chekiangenesis_ are two important endemic species in China. _P. zhennan_, mainly distributed in Sichuan, Chongqing, and Guizhou Provinecs, is historically renowned for its durable, aromatic timber used in ancient palatial architecture [8; 9]. _P. chekiangenesis_, native to Zhejiang and neighboring regions, is valued for its dense canopy, ornamental characteristics, and fragrant wood and is listed as a nationally protected species due to habitat loss and overuse [10; 11]. Both species are widely planted in urban landscapes and ecological restoration because of their evergreen foliage, shade tolerance, and pest resistance. Their wood and foliage emit distinct pleasant aromas, mainly derived from volatile secondary metabolites such as monoterenes, sesquiterpenes, and phenylpropanoids [12; 13]. While previous studies have explored terpenoid-rich extracts from _Phoebe_ wood for antimicrobial and antioxidant activities, detailed volatile metabolite profiles of _P. zhennan_ and _P. chekiangenesis_, especially in non-wood tissues like seeds and leaves, remain scarce. To date, no study has systematically compared their aroma-active metabolomics across different organs, despite known organ- and species-related scent differences. A systematic metabolomic investigation is thus needed to clarify the biochemical basis of their aroma divergence and guide efforts to utilize their aroma and improve their germplasm. Recent analytical advances have enabled the systematic profiling of plant volatiles [14]. Gas chromatography-mass spectrometry (GC-MS) remains a widely used and robust method for VOC analysis due to its high sensitivity and compound identification accuracy [15; 16]. In addition, the relative odor activity value (rOAV) provides a quantitative approach to evaluate each compound's sensory contribution by combining chemical concentration with odor thresholds [17; 18]. rOAV-based screening has become increasingly important for identifying key aroma-active compounds in complex plant samples [19]. Moreover, aroma flavoromics is a strategy that combines metabolite annotation with known odor descriptors. It has gained traction in the study of aroma characteristics in foods, medicinal plants, and aromatic trees [20; 21; 22]. By integrating metabolomic data, aroma information, and pathway enrichment analyses such as Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation, researchers can unravel species- and organ-related aroma traits with a high resolution. However, despite the widespread application of metabolomics in herbaceous plants and fruits [15; 16], its use in long-lived woody species like _Phoebe_ remains relatively limited. Current studies mainly focus on wood extracts or essential oils, while the volatile metabolomes of seeds and leaves, which are organs with distinct ecological functions, remain largely uncharacterized.