Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
Environ Sci Pollut Res Int. 2015 Jul;22(14):11109-17. doi: 10.1007/s11356-015-4325-x. Epub 2015 Mar 22.
Toxicity of engineered nanoparticles on organisms is of concern worldwide due to their extensive use and unique properties. The impacts of ZnO nanoparticles (ZnO NPs) on seed germination and root elongation of corn (Zea mays L.) and cucumber (Cucumis sativus L.) were investigated in this study. The role of seed coats of corn in the mitigation toxicity of nanoparticles was also evaluated. ZnO NPs (1,000 mg L(-1)) reduced root length of corn and cucumber by 17 % (p < 0.05) and 51 % (p < 0.05), respectively, but exhibited no effects on germination. In comparison with Zn(2+), toxicity of ZnO NPs on the root elongation of corn could be attributed to the nanoparticulate ZnO, while released Zn ion from ZnO could solely contribute to the inhibition of root elongation of cucumber. Zn uptake in corn exposed to ZnO NPs during germination was much higher than that in corn exposed to Zn(2+), whereas Zn uptake in cucumber was significantly correlated with soluble Zn in suspension. It could be inferred that Zn was taken up by corn and cucumber mainly in the form of ZnO NPs and soluble Zn, respectively. Transmission electron microscope confirmed the uptake of ZnO NPs into root of corn. Although isolation of the seed coats might not be the principal factor that achieved avoidance from toxicity on germination, seed coats of corn were found to mitigate the toxicity of ZnO NPs on root elongation and prevent approximately half of the Zn from entering into root and endosperm.
由于工程纳米粒子的广泛应用和独特性质，其对生物体的毒性引起了全球关注。本研究考察了氧化锌纳米粒子（ZnO NPs）对玉米（Zea mays L.）和黄瓜（Cucumis sativus L.）种子萌发和根伸长的影响。还评估了玉米种皮在减轻纳米粒子毒性方面的作用。ZnO NPs（1000mg/L）分别使玉米和黄瓜的根长减少了 17%（p<0.05）和 51%（p<0.05），但对萌发没有影响。与 Zn(2+)相比，ZnO NPs 对玉米根伸长的毒性可归因于纳米 ZnO，而 ZnO 释放的 Zn 离子仅可导致黄瓜根伸长的抑制。在萌发过程中，暴露于 ZnO NPs 的玉米中 Zn 的吸收量远高于暴露于 Zn(2+)的玉米，而黄瓜中 Zn 的吸收量与悬浮液中的可溶性 Zn 显著相关。可以推断，Zn 主要以 ZnO NPs 和可溶性 Zn 的形式被玉米和黄瓜吸收。透射电子显微镜证实了 ZnO NPs 被吸收到玉米根中。虽然分离种皮可能不是避免毒性对萌发影响的主要因素，但玉米种皮被发现可减轻 ZnO NPs 对根伸长的毒性，并防止约一半的 Zn 进入根和胚乳。
