摘要
采用发芽实验研究环丙沙星对玉米发芽率和幼苗生长的影响.测定了不同浓度(0.5—50 m.gL-1)环丙沙星处理下玉米的发芽率、生物量、自由基水平、脂质过氧化产物(MDA)含量、抗氧化酶活性和对环丙沙星的吸收与累积.结果显示,玉米对环丙沙星的吸收和传输随着暴露液中环丙沙星浓度的增加而上升.在实验浓度范围内,环丙沙星不影响玉米的发芽率,但幼苗的生长受到不同程度抑制,敏感程度依次为根重>根长>芽长>芽重.环丙沙星暴露使玉米根和芽中脂质过氧化产物丙二醛(MDA)含量显著升高,根中谷胱甘肽硫转移酶(GST)、过氧化氢酶(CAT)、过氧化物酶(POD)和超氧化物歧化酶(SOD)活性变化显著,均呈现低浓度下被激活而高浓度下被抑制的趋势.通过自旋捕集/电子顺磁共振技术发现环丙沙星显著提高了根中羟基自由基含量,表明大量羟基自由基的产生是环丙沙星对玉米氧化损伤的重要原因.
Wide application of antibiotics in disease treatment and animal feed additives have led to increasing levels of these highly bioactive substances in the environment and constituted a potential risk to ecosystem and public health.To investigate the phytotoxicity of ciprofloxacin（CIP） on maize（Zea mays L.） early stage development,germination test was carried out and germination rate,seedling biomass,free radical level,lipid peroxidation product content,antioxidative enzyme activities and CIP uptake and accumulation were assayed after 7-day exposure to different concentrations of CIP.It is shown that both the uptake and transport of CIP by maize increased with the increase of the antibiotic in exposure solution.0.5— 50 mg·L-1 of CIP did not inhibit germination rate.Maize growth（indicated by both root and shoot） was inhibited under all concentrations tested and the susceptibility of the endpoints followed the orders of root fresh weightroot lengthshoot heightshoot fresh weight.Lipid peroxide malonaldehyde（MDA） in both root and shoot increased with increasing CIP concentration.Activities of glutathione s-transferase（GST）,catalase（CAT）,peroxidase（POD） and superoxide dismutase（SOD） in root were induced by lower CIP but inhibited by higher CIP.All the results showed oxidative stress caused by CIP.Furthermore,with an secondary spin trapping coupled with electron paramagnetic resonance（EPR） technique,higher level of free radicals was detected in maize root treated by CIP,providing a direct evidence for oxidative stress on maize seedlings by CIP exposure.
出处
《环境化学》
CAS
CSCD
北大核心
2011年第4期753-759,共7页
Environmental Chemistry
基金
国家自然科学基金项目(No.20737003
No.20877087)
国家重点基础研究发展计划(973)项目(No.2009CB421603)资助
