biologia plantarum

Biologia plantarum 53:151-154, 2009 | DOI: 10.1007/s10535-009-0023-1

Cadmium-induced oxidative damage and antioxidant responses in Brassica juncea plants

Y. K. Markovska^1,*, N. I. Gorinova², M. P. Nedkovska², K. M. Miteva¹

¹ Department of Plant Physiology, Faculty of Biology, University of Sofia, Sofia, Bulgaria

² AgroBioInstitute, Sofia, Bulgaria

Indian mustard (Brassica juncea L. cv. Vitasso) plants exposed to 10, 30, 50 and 100 µM of Cd for 5 d in hydroponic culture were analysed with reference to the distribution of Cd²⁺, the accumulation of biomass and antioxidants and antioxidative enzymes in leaves. Cd induced a decrease in plant biomass. The maximum accumulation of Cd occurred in roots followed by stems and leaves. Cd induced a decrease in catalase (CAT) and guiacol peroxidase (GPX) activities but an increase in ascorbate peroxidase (APX) and monodehydroascorbate reductase (MDHAR) activities. Enhancement in dehydroascorbate reductase (DHAR) activity was also at 10 µM Cd. Glutathione reductase (GR) activity showed pronounced stimulation after all treatments, but glutathione S-transferase (GST) and glutathione peroxidase (GPOX) activities decreased. The effectiveness of ascorbate-glutathione cycle (AGC) was determined by the ratio of ascorbate to H₂O₂. This ratio decreased in the Cd-treated leaves which indicated that the cycle was disordered.

Keywords: ascorbate-glutathione cycle; catalase; Indian mustard; guiacol peroxidase

Subjects: ascorbate peroxidase; Brassica juncea; cadmium; catalase; dehydroascorbate reductase; glutathione; glutathione reductase; glutathione-S-transferase; guaiacol peroxidase; hydrogen peroxide; Indian mustard; lipid peroxidation; malondialdehyde; monodehydroascorbate reductase; peroxidase

Received: May 9, 2007; Accepted: January 5, 2008; Published: March 1, 2009  Show citation