Updated project metadata. Tieguanyin (TGY) and Shuixian (SX) cultivars of Camellia sinensis were selected to explore the mechanism underlying the accumulation of the rare earth element lanthanum through proteomics. Roots and fresh leaves of TGY and SX with low- and high-accumulation potential for lanthanum, respectively, were studied; 845 differentially expressed proteins (DEPs) were identified. Gene ontology analysis showed that the DEPs are involved in redox processes and related to molecular functions, such as defense and oxidative stress reactions, catalytic activity, and metal ion binding. Kyoto Encyclopedia of Genes and Genomes metabolic pathway analysis showed that DEPs were associated with glutathione (GSH) and α-linolenic acid metabolism, plant pathogen interaction, and oxidative phosphorylation. Thirty-seven proteins in the GSH metabolism pathway showed significant differences, of which 18 GSH S-transferases show differential expression patterns in the root system.The expression multiples of GST (TEA004130.1) and GST (TEA032216.1) in T1L and T0L were 6.84 and 4.06, respectively, which were significantly higher than those in S1L and S0L. The lanthanum-induced activation of the GSH-related antioxidant defense system may cause the difference in TGY and SX. The LOX2.1 (TEA011765.1) and LOX2.1 (TEA011776.1 expression ratios) in the α-linolenic acid metabolic pathway were 2.44 and 6.43 in T1R and T0R, respectively, which were significantly higher than those in S1R snd S0R. The other differential proteins were also sig-nificantly upregulated in TGY leaves.The synthesis of specific substances induces lantha-num-associated defense responses in TGY, which is of great significance for the stability of its yield.