Fig. 4

Differentially expressed genes (DEGs) during seed development. A The number of up- and down-regulated DEGs for each comparison group. B Venn diagrams showing the unique and common DEGs in various comparison groups (S2 vs. S1; S3 vs. S1; S4 vs. S1; and S5 vs. S1). C Cluster analysis of the expression profiles for DEGs at five stages of seed development. The Y-axis shows normalized fold-changes in gene expression, and the X-axis indicates each stage; there were three independent biological replicates for each time point. D Heatmap of the normalized abundances of transcripts in alfalfa seeds during each development stage. Alfalfa seeds were obtained at 11, 19, 27, 35, and 43 days after pollination, and the time points were designated as S1, S2, S3, S4, and S5, respectively