Fig. 4

Amino acids and their derivatives of the upper translucent part and the bottom chalky part. 05, 10, 15, and 20, days after anthesis. Red and green indicate p ≤ 0.05 (red denotes significant increase in the chalky endosperm, green significant decrease). Pink red and light green indicate 0.05 < p < 0.10 (pink red indicates increase while light green decrease). Refer to Additional file 1: Table S1 for detailed information of the changes of these metabolites