Certain antioxidant enzymes and lipid peroxidation of radish (Raphanus sativus L.) as early warning biomarkers of soil copper exposure.
Copper (Cu) is a major heavy metal contaminant with various anthropogenic and natural sources. Recently, using biomarkers to monitor the effects of pollutants has attracted increased interest. Pot culture experiments using radish (Raphanus sativus L.) was performed to investigate Cu phytotoxic effects on antioxidant enzymes and other early warning biomarkers of soil Cu exposure. Under low dose Cu stress (lower than the EC10, Cu concentration reducing root length by 10%), activity and isozyme expression of superoxide dismutase (SOD), catalase (CAT), and peroxidases (POD) increased significantly; no significant variations in chlorophyll, carotenoid, and malondialdehyde (MDA) content in leaves and toxic symptoms were observed. Under a slightly higher Cu stress (close to the EC10), activity and isozyme expression of SOD and MDA content were enhanced significantly; those of CAT and POD decreased due to an inverted U-shape dose response. Chlorophyll content remained unchanged. Thus, antioxidant enzymes and MDA content are more sensitive to Cu stress, showing significant variations ahead of chlorophyll and toxic symptoms under Cu stress (lower than about 200 mg kg(-1) soil). Thus, the joint monitoring of antioxidant enzymes and MDA content of R. sativus can be used as biomarkers of soil Cu contamination.
Sun
Bai-Ye
BY
Provincial Key Laboratory of Agro-Environmental Engineering, College of Resources and Environment, Sichuan Agricultural University, Sichuan, Ya'an 625014, People's Republic of China.
Kan
Shi-Hong
SH
Zhang
Yan-Zong
YZ
Deng
Shi-Huai
SH
Wu
Jun
J
Yuan
Hao
H
Qi
Hui
H
Yang
Gang
G
Li
Li
L
Zhang
Xiao-Hong
XH
Xiao
Hong
H
Wang
Ying-Jun
YJ
Peng
Hong
H
Li
Yuan-Wei
YW
D000975:Antioxidants / Q000032:analysis; D015415:Biomarkers; D002338:Carotenoids / Q000032:analysis; D002734:Chlorophyll / Q000032:analysis; D003300:Copper / Q000032:analysis / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring / Q000379:methods*; D015227:Lipid Peroxidation; D008315:Malondialdehyde / Q000032:analysis; D010088:Oxidoreductases / Q000032:analysis*; D018515:Plant Leaves / Q000378:metabolism; D031224:Raphanus / Q000378:metabolism*; D012989:Soil Pollutants
D000975:Antioxidants; D015415:Biomarkers; D012989:Soil Pollutants; D002734:Chlorophyll; D002338:Carotenoids; D008315:Malondialdehyde; D003300:Copper; D010088:Oxidoreductases