Figure 6.

GA content in Icaro (Rht18), Castelporziano (Rht14), and respective tall isolines and enzyme activity of GA2oxA9 from Icaro (Rht18) and tall isoline (M24). A to E, Content of GA precursors GA₅₃, GA₁₉, and GA₂₀ (A–C), bioactive GA₁ (D), and inactive catabolite GA₈ (E; ng/g FW) in rapidly elongating peduncle tissue from tetraploid wheat lines. Data are mean values of three biological replicates ± se. Different letters indicate significant differences between Icaro (Rht18), M24, and Anhinga (ANOVA, P < 0.05). Significant differences between Castelporziano (Rht14) compared to Capelli are indicated by asterisks (Student’s t test,*P < 0.05, **P < 0.01, and ***P < 0.001). F, Adjusted peak areas of ¹⁴C-GA₁₂ and product ¹⁴C-GA₁₁₀ following 1 h incubation of ¹⁴C-GA₁₂ with cell-free extracts from E. coli expressing GA2oxA9 from Rht18 (Icaro), tall mutant (M24), and empty vector control monitored by liquid chromatography-tandem mass spectrometry. Extracts from E. coli with empty vector control had no detectable (nd) ¹⁴C-GA₁₁₀.