Figure 2.

(A) Regulatory network of AtTTG1-dependent pathways in Arabidopsis illustrating the potential/indirect (broken black lines) and demonstrated (unbroken black lines) interactions among proteins/genes. Boxed are regulated processes. Key: green heptagons, WDR-containing protein AtTTG1; red ovals, bHLH transcription factors from subgroup IIIf; blue ovals, activator-type R2R3-type MYB subfamilies; yellow ovals, repressor-type R2R3-type MYBs; purple ovals, repressor-type R3-type MYB subfamilies. Note the narrowing of regulatory specificity across the tiers from top to bottom. (B) Schematic representation of MYB-bHLH-TTG1 (MBW) complexes regulating flavonoid defense metabolism and other processes in representative plant species of major clades within flowering plants (monocot vs. dicot, asterid vs. rosid, different rosid orders). Dotted lines indicate potential genetic/physical interactions. Note the functional conservation of MBW complexes in the regulation of flavonoid biosynthesis across different plant species.