title: [Biological responses of maize seedlings to single and combined stress of cadmium and phenanthrene].
abstract: Maize (Zea mays L.) pot-culture experiments were conducted in this study for exploring the biological responses of maize seedlings to single and joint stress of Cadmium (Cd) and phenanthrene. The results showed that single-Cd treatment with Cd concentration ranging from 0 to 50 mg/kg had no significant influences on the above-ground biomass, root biomass, and the soluble protein of maize seedlings; with the increase of Cd concentrations, the maize leaf SOD activities appeared as an increasing-decreasing trend, while the POD, CAT, APX activities increased persistently. The APX is very sensitive to Cd stress, which increased 38% than control treatment at lower Cd treatment (1 mg/kg). The accumulation of O2-* is one of the main cause of single-Cd toxicity. Under the Cd-phenanthren combined stress, the SOD activity increased at lower Cd concentration (1 mg/kg) , which can reached to 1.66 times of control treatment, and decreased when Cd concentration becomes high. The SOD activity is a sensitive index in response to the Cd-phenanthren combined pollution. Unlike SOD activity, the activities of POD, CAT and APX were obviously induced by combined pollution of Cd and phenanthren; but these enzyme activities decreased when compared with the single-Cd stress, which suggested that the combined toxicity of Cd and phenanthrene is stronger than the single-Cd stress. And the accumulation of O2-* and *OH is one of the main cause of Cd-phenanthrene combined toxicity.
authors.affiliation: Jiangsu Key Laboratory of Agricultural Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China. xianghua_xu@163.com
authors.forename: Xiang-hua
authors.initials: XH
authors.lastname: Xu
authors.forename: De-fu
authors.initials: DF
authors.lastname: Xu
authors.forename: Xiao-rong
authors.initials: XR
authors.lastname: Wang
authors.forename: Ji-chun
authors.initials: JC
authors.lastname: Wu
authors.forename: Ren-zhang
authors.initials: RZ
authors.lastname: Lin
mesh_terms: D002104:Cadmium / Q000633:toxicity*; D010616:Phenanthrenes / Q000633:toxicity*; D036226:Seedlings / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D013312:Stress, Physiological; D013482:Superoxide Dismutase / Q000378:metabolism; D003313:Zea mays / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*
chemical_list: D010616:Phenanthrenes; D002104:Cadmium; C031181:phenanthrene; D013482:Superoxide Dismutase