Oxidative response and antioxidative mechanism in germinating soybean seeds exposed to cadmium.
Seeds of soybean (Glycinemax L.) exposed to 50 mg/L (Cd50), 100 mg/L (Cd100) and 200 mg/L (Cd200) cadmium solution for 24, 48, 72 and 96 h were examined with reference to Cd accumulation, oxidative stress and antioxidative responses. Soybean seeds accumulated Cd in an exposure time-and dosage-dependent manner. FRAP (ferric reducing ability of plasma) concentration, GSH/hGSH content, and GST activity showed a pronounced exposure time-dependent response. Cd100 enhanced FRAP concentration in germinating soybean seeds as compared to Cd50 treatment after 24 h exposure. Cd200 however increased statistically GST activities after 72 and 96 h exposure. Under all Cd dosages, GSH/hGSH concentrations were depressed with increasing exposure time. Reduction of GSH/hGSH content and concomitant increase of GST activity suggested a possible participation of GSH into GSH-Cd conjugates synthesis. MDA content is a potential biomarker for monitoring Cd phytotoxicity because it responds significantly to treatment dosage, exposure time and dosage × exposure time interaction. Increase of proline content may be a response to acute heavy metal toxicity in soybean seeds.
Section of Ecology, School of Life Sciences, Anhui Normal University, Wuhu, China. shiyan@mail.ahnu.edu.cn
Shiyong
S
Yang
Jianchun
J
Xie
Quanfa
Q
Li
D000975:Antioxidants / Q000378:metabolism; D002104:Cadmium / Q000378:metabolism*; D018525:Germination; D005978:Glutathione / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D015227:Lipid Peroxidation; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress; D011392:Proline / Q000378:metabolism*; D012639:Seeds / Q000378:metabolism; D013025:Glycine max / Q000378:metabolism*; D013997:Time Factors
D000975:Antioxidants; D002104:Cadmium; D008315:Malondialdehyde; D011392:Proline; D005982:Glutathione Transferase; D005978:Glutathione