GSR and hyperinsulinemic hypoglycemia, familial, 4: In this study, S-deficiency, Cd stress under S-deficiency and Cd stress during sufficient S decreased the GSH/GSSG ratio, from 4.50 in the control to 4.23 (−S/−Cd), 3.81 (−S/+Cd) and 3.63 (+S/+Cd) at 14 DAT, showing a ratio-maintaining capability of plant only in the presence of sufficient S. The data suggest a direct correlation between GR activity and GSH/GSSG ratio.