Gas chromatography-time-of-flight mass spectrometry (GC-TOFMS)-based metabonomic response of <i>Salvia miltiorrhiza</i> flowers to cadmium stress

Cd-treated groups, respectively. These DMs were mainly enriched in alanine, aspartate and glutamate metabolism, glyoxylate and dicarboxylate metabolism, butanoate metabolism, citrate cycle (TCA cycle), and glycine, serine and threonine metabolism. Among the metabolites, oxamic acid and citric acid contributed most to the down-regulated differential amino acids and differential organic acids, respectively; xylose and 1-kestose contributed most to the up-regulated differential sugars; tryptophan and arachidic acid contributed most to the up-regulated amino acids and organic acids, respectively. These findings suggested that SM flowers might resist Cd stress through restructuring the cell-wall framework, modulating membrane fluidity, and regulating intracellular soluble components. These findings provide new avenues for exploring how medicinal plant resources cope with heavy-metal stress.