Fig. 5

The relative expression level between RT-qPCR and RNA-seq data of genes involved in flavonoid and carotenoid biosynthesis. The relative expression value was calculated using the 2^−ΔΔCt method with β-actin gene of Salix as internal control. Error bars represent the mean ± SD of three biological replicates (n = 3). FRKM, fragments per kilobase of exon per million mapped fragments; G, green bark; P, purple bark; R, red bark