玉米幼苗对镉、菲单一与复合污染的生理生化响应

通过室内盆栽实验研究了玉米幼苗在镉、菲污染胁迫14 d后的生理生化响应,并探讨了镉、菲单一与复合污染对玉米幼苗的毒性效应及其致毒机制.结果表明,单一镉(0～50 mg/kg)污染时,镉处理对玉米幼苗地上部分和根系生物量以及可溶性蛋白都无显著影响;随镉处理浓度的增加,玉米幼苗叶片SOD酶活性表现为先增加后降低的趋势,而P...

Biological Responses of Maise Seedlings to Single and Combined Stress of Cadmium and Phenanthrene

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 O^-·₂ is one of the main cause of single-Cd toxicity. Under the Cd-phenanthren combined stress,the SOD activity increased at lower Cd concentration (1mg/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 O^-·₂ and ·OH is one of the main cause of Cd-phenanthrene combined toxicity.