Fig. 3. Schematic of Cd + Se or Cd stress-responsive primary metabolites in the leaves (green) and roots (red) of cucumber seedlings. Each detected metabolite framed with continuous lines was significantly down-accumulated in Cd-treatment and up-accumulated or unchanged in Cd + Se treatment, and those framed with dotted lines were significantly up-accumulated in Cd-treated cucumber seedlings. Metabolites in bold were checked in both leaves and roots. The relative fold changes in abundance are shown in Tables 1–4.