Abstract: We compared the difference of metabolite components of wild ancient tea (Camellia talinensis) along an altitudinal gradient (2050, 2200, 2350, 2500 m) of Qianjiazhai Reserve in Yunnan Province by UPLC-MS/MS, to explore the physiological and metabolic response and adaptation at different altitudes. The results showed that a total of 12 categories of metabolites and 1013 metabolites in C. talinensis were detected on the four altitudes. Flavonoids were the most common (23.10%), followed by phenolic acids (16.68%). A total of 430 differential metabolites were selected, with 75 shared differential metabolites. More flavonoids were enriched at 2050 m altitude, and more amino acids and their derivatives, nucleotides and their derivatives, alkaloids and lipid metabolites at 2200 m altitude. Phenolic acids and organic acids increased significantly at altitudes of 2350 m and 2500 m. In addition, different metabolites were significantly enriched in the flavonoid biosynthesis pathway, caffeine metabolism pathway and amino acid metabolism pathway at different altitudes. With increasing altitude, key metabolites of flavonoid pathway showed a down-up-down trend, while the key metabolites of caffeine and amino acid pathway showed a first increasing and then decreasing trend.

Key words: altitude, Camellia talinensis, UPLC-MS/MS, metabolomics, metabolite