Cadmium-Induced Hydrogen Accumulation Is Involved in Cadmium Tolerance in Brassica campestris by Reestablishment of Reduced Glutathione Homeostasis.

Abstract

This study examined the physiological role of hydrogen-rich water (HRW) in Brassica campestris seedlings exposed to cadmium (Cd) stress. Both 50 μM CdCl2 and HRW at 50% saturation elevated endogenous H2 levels. HRW application reduced growth inhibition and oxidative damage caused by Cd. Seedlings receiving HRW showed greater root elongation, lower lipid peroxidation, elevated reduced glutathione (GSH) and ascorbic acid (AsA) concentrations, and higher GST and GPX enzymatic activities in roots. At the molecular level, expression of GS, GR1, and GR2 genes—suppressed by Cd, GSH, or BSO—was partially restored by HRW supplementation. These findings indicate that H2 functions as a regulator of GSH homeostasis, thereby enhancing Cd tolerance in Brassica campestris seedlings.

Mechanism

H2 restores expression of GSH biosynthesis and recycling genes (GS, GR1, GR2), thereby re-establishing reduced glutathione and ascorbic acid homeostasis and mitigating cadmium-induced oxidative stress in plant roots.