Gene ontology (GO) functional classification of DEGs from four treatment groups in B. napus. A total of 4784 DEGs were classified into GO terms from three ontologies involving cellular components (A), molecular function (B), and biological processes (C). CK-L (CK, leaves) vs. D-L (drought, leaves), CK-R (CK, roots) vs. D-R (drought, roots), CK-L vs. S-L (salinity, leaves), CK-R vs. S-R (salinity, roots) represent DEGs under these two abiotic stresses. The y-axis on the right indicates the number of genes in each category. The y-axis on the left indicates the percentage of specific genes in each category.