Key enzymatic genes highly expressed in root (colored red, consistent with the accumulation of the pigmented tanshinones in this organ), leaf and flower. In addition, the root was further divided into four cross-section cell-types, roughly correlated to the periderm (colored red, consistent with the more specific localization of tanshinones in this cell-type), cortex, phloem and xylem, and those genes known to have higher expression in these cell-types also are indicated. Red text indicates genes with known roles in tanshinone biosynthesis and those known to exhibit inducible expression with an asterisk (*)