Cadmium affects glutathione-related metabolism in Vicia faba roots

Cadmium (Cd) is one of the most toxic heavy metals in plants. To investigate whether Cd induces common plant defense pathways, different physiological and molecular reactions, including modifications in glutathione (GSH) level, activity and gene expression of glutathione reductase (GR) enzyme were characterized in roots of hydroponically cultivated-Vicia seedlings during 12, 24 and 48 h. Vicia roots which accumulated the metal, showed an increase in GR1-like gene transcripts, encoding for GR enzyme, as earlier as 12 h after the onset of the Cd treatment while the root growth was not as yet affected by the Cd treatment. When Vicia roots exposure was longer (24 h and 48 h), metal induced significant decreases in fresh (FW), dry weight (DW) and water content. These growth changes were accompanied by progressively increases in GR activity, GSH and oxidized glutathione (GSSG) level.