MapMan overview showing regulatory genes that are differentially expressed in alfalfa genotypes 252 and 1283 in ES (A) and PES (B) internodes. Individual genes are represented by small squares. The Log2(252/1283) values for the differentially expressed genes (p < 0.001, FDR < 0.05, ≥ 2-fold difference) were false color coded using a scale of -3 to +3. The intensity of blue and red colors indicates the degree of preferential expression of the corresponding genes in 252 and 1283, respectively. Color saturates at ±3 (8-fold difference or higher). See Methods for details. A complete list of the differentially expressed genes, corresponding MapMan functional categories, signal intensities and log ratios are provided in Additional file 1.