title: Oxidative stress and potential biomarkers in tomato seedlings subjected to soil lead contamination.
abstract: Oxidative stress and defense response in leaves of tomato seedlings exposed to extraneous lead (Pb) at 0-500 mg kg(-1) soil for nearly 2 months were investigated. Superoxide radical (O(2)(-)) was quantified by electron paramagnetic resonance (EPR). Results showed that levels of O(2)(-), malondialdehyde (MDA), carbonyl group and superoxide dismutase (SOD) increased with the increase of bioavailable Pb. The O(2)(-) level was well correlated with MDA, carbonyl groups and SOD activities, suggesting that O(2)(-) might be responsible for them. Intensities in two bands of SOD isoenzymes increased along with added Pb in treatments against control, implying that multigenic expression in SOD enzymes were activated to counteract O(2)(-) stress. Heat shock protein 70 (HSP70) was induced sensitively by soil Pb, which was to alleviate oxidative damage (i.e. increased carbonyl groups). The overall results indicated that HSP70 and O(2)(-) were the most sensitive parameters and the combination of them might be potential biomarkers of soil Pb contamination in tomato seedlings.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210093, China.
authors.forename: Chengrun
authors.initials: C
authors.lastname: Wang
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Wang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Tian
authors.forename: Yingang
authors.initials: Y
authors.lastname: Xue
authors.forename: Xianghua
authors.initials: X
authors.lastname: Xu
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Sui
authors.forename: Hongxia
authors.initials: H
authors.lastname: Yu
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D007854:Lead / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D015227:Lipid Peroxidation / Q000187:drug effects; D018551:Solanum lycopersicum / Q000187:drug effects* / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects* / Q000378:metabolism; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism
chemical_list: D015415:Biomarkers; D018840:HSP70 Heat-Shock Proteins; D012987:Soil; D012989:Soil Pollutants; D013481:Superoxides; D007854:Lead; D008315:Malondialdehyde; D013482:Superoxide Dismutase