Fig. 4

The hierarchical cluster analysis (HCA) of the metabolite profiles in tall fescue. There were four treatment regimes in this study, including the Con, Cd treatment, T1 treatment, and T2 treatment, and each regime had three replicates. They respectively presented the tall fescue seedlings were cultivated in 1/2 Hoagland solution (Con), 1/2 Hoagland solution with 50 mg/L Cd²⁺ (CdCl₂•2.5H₂O) (Cd treatment), 1/2 Hoagland solution with 50 mg/L Cd²⁺ and 200 μM SNP (T1 treatment), and 1/2 Hoagland solution with 50 mg/L Cd²⁺, 200 μM L-NAME and 100 μM c-PTIO (T2 treatment)