Fig. 4
Histograms showing relative expression levels of homeologous genes in the studied allotetraploid transcriptomes. a, b Data from stem apex. c, d Data from leaf tissue. a, c for A. alpina; b, d for A. wilsoniana. The abscissa is Rh [log2 (acu-homeolog/asi-homeolog)], and the ordinate is the number of homeolog pairs. Gray columns correspond to homeolog pairs with equal expression level of two parental copies; light blue columns correspond to homeolog pairs with higher expression of the A. asiatica-copy, and vise versa, dart blue columns correspond to homeolog pairs with higher expression of the A. acuminata-copy (P-value < 0.05, FDR < 0.05). Numbers at the upper right corner indicate the number of homeolog pairs of each category