Transcript abundance for 13 spruce MYB genes and 4CL in various organs and tissues. Transcript abundance was determined by Q-RTPCR of six tissues from two different 33-year-old trees (number of molecules per ng of total RNA, see methods). The transcript level of an elongation factor (EF1-α) gene was used as an RNA control. N, needles; Stem tissues: P, periderm; Ph, differentiating phloem; X, differentiating xylem; Root tissues: PPh, root periderm with differentiating phloem; X, root differentiating xylem. Data are based on three technical repetitions per tree, i.e. six measurements per data point. Vertical bars represent the standard error. 4CL: 4-coumarate: CoA ligase. NS, no PCR product detected.