## 4 Conclusions  
By employing HS-GC-IMS and HS-SPME-GC-MS techniques alongside PLS-DA modeling, this study delineated significant alterations in the VOCs of FD and WNZ tea cultivars subjected to drought stress. The drought-stressed groups exhibited a marked increase in both the concentration and diversity of VOCs associated with sweet, fruity, caramel-like, floral, and earthy notes, while green, grassy, leafy, woody, herbal, and floral aromas were diminished. Notably, there was an elevated presence of methylated compounds, linalool oxides, and medium- to long-chain VFADs in the drought-treated samples. Conversely, sesquiterpenoid content and diversity were substantially reduced. The varietal responses to drought stress were distinct, with FD-D showing an increased diversity of VOCs, whereas WNZ exhibited a greater increase in the concentrations of low-threshold VOCs. Among the four sample groups, key aroma-active compounds (OAV \(>1\)) included 1-Octen-3-ol, linalool, geraniol, \(\beta\)-damascone, (E)-\(\beta\)-ionone, citral, and \(\beta\)-myrcene, with linalool exhibiting the highest OAV, underscoring its role as a primary aroma contributor in both tea cultivars. Based on VIP \(>1\) and OAV \(>1\) thresholds, 8 and 13 potential key aroma markers were identified for distinguishing between the different cultivars and treatments using the PLS-DA model for HS-GC-IMS and HS-SPME-GC-MS, respectively. Additionally, KEGG enrichment analysis revealed significant alterations in 12 metabolic pathways following drought stress. The sesquiterpenoid and triterpenoid biosynthesis pathways, as well as monoterenoid biosynthesis, exhibited significant changes (_p_ < 0.05). Furthermore, pathways related to fatty acid synthesis, elongation, degradation, the biosynthesis of unsaturated fatty acids, linalool oxides, cutin, suberine and wax biosynthesis, and phenylalanine metabolism were also enriched, further validating the observed increases in the abundance and diversity of linalool oxides and medium- to long-chain VFADs, along with the pronounced reduction in sesquiterpenoid compounds under drought stress. Overall, these results provide a comprehensive insight into how drought stress affects VOC accumulation in fresh tea leaves across different cultivars, while highlighting the corresponding alterations in key metabolic pathways. This knowledge establishes a foundation for optimizing water management strategies in tea plant cultivation, aiming to enhance flavor quality. The current study relies on metabolomics and flavoromics to analyze key volatile aroma compounds and their metabolic pathways in tea leaves subjected to 20 days of continuous field drought stress. However, the absence of physiological or genetic data linking VOC changes to drought resistance presents a limitation. Future research will aim to integrate physiology, transcriptomics, and DNA methylation data to elucidate the molecular mechanisms governing VOC accumulation and aroma formation in tea under drought stress. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/foods13213412/s1](https://www.mdpi.com/article/10.3390/foods13213412/s1)]([https://www.mdpi.com/article/10.3390/foods13213412/s1](https://www.mdpi.com/article/10.3390/foods13213412/s1)), Figure S1.