Effects of nitrogen and sulfur on the differentially accumulated transcripts and metabolites by grain developmental stage. On the left, histograms show the number of DEGs, and on the right, lollipop charts represent the LFC of significant metabolites, by treatment comparison and by grain developmental stage. Upregulation and downregulation of transcripts and metabolites was based on a comparison between the first and second treatments and reflect a significant higher (up-regulated) or lower (down-regulated) accumulation in the first compared to the second treatment. In the lollipop charts, dot size represents −log10 of the FDR values. AA, total free amino acids; GSH, reduced glutathione; GSSG, oxidized glutathione; Glut, glutathione; Pyr, pyrroline-5 carboxylate.