纳米管和镉对蚕豆幼苗根系的毒害效应

Toxic Effects of Carbon Nanotubes and Cadmium Treatments on Root Growth of Vicia faba Seedlings

以蚕豆幼苗为实验材料,采用水培法研究不同浓度(0、2、4、8、16 mg·L^-1)羟基化多壁碳纳米管(MWCNTs-OH)与10μmol·L^-1镉(Cd)单一和联合作用对蚕豆幼苗根系生长、生理及Cd含量的影响。结果表明:(1)单一MWCNTs-OH处理下,随着MWCNTs-OH浓度(2~8 mg·L^-1)的增加,蚕豆的根长度增加,且■产生速率增加的同时会伴随着SOD、POD活性升高。(2)单一Cd处理的幼苗根系MDA含量和■产生速率均高于对照,其中■产生速率较对照增加了1.98倍。(3)MWCNTs-OH联合处理诱导了蚕豆根■的产生和MDA含量增加,16 mg·L^-1 MWCNTs-OH和Cd共同作用对蚕豆幼苗根的损伤最大,会促使部分根尖细胞受损脱落,Cd含量明显下降。研究发现,低浓度MWCNTs-OH可促进蚕豆的根生长,降低Cd的毒性;高浓度MWCNTs-OH(16 mg·L^-1)和Cd对蚕豆幼苗根的致毒性表现为协同效应。

In order to reveal the effects of single and combined treatment with different concentrations(0, 2, 4, 8, 16 mg·L^-1) of hydroxylated multi walled carbon nanotubes and 10 μmol·L^-1 Cd, we studied root growth physiological indexes and Cd content of Vicia faba seedlings by hydroponic method. The results showed that:(1) with the treatment of single MWCNTs-OH, with the increase of MWCNTs-OH concentration(2-8 mg·L^-1), the length of V. faba root increased, and the production rate of ■ increased along with the increase of SOD and POD activities.(2) The MDA content and ■ production rate of seedlings treated with single Cd were both higher than that of the control group, and the ■ production rate was 1.98 times higher than that of the control group.(3) The MWCNTs-OH combined treatment induced the production of ■ and the increase of MDA content in the root of V. faba seedlings. The 16 mg·L^-1 MWCNTs-OH combined with Cd caused the greatest damage to the root of V. faba seedlings, and some root tip cells were damaged and shed, and Cd content was significantly decreased. It was found that low concentration of MWCNTs-OH could promote root length and reduce the toxicity of Cd, while high concentration(16 mg·L^-1) of MWCNTs-OH combined with Cd had a synergistic effect on root toxicity of V. faba seedlings.