| 王苗苗,强沥文,王伟,张克强,孙斌斌.纳米二氧化钛对镉胁迫下小白菜毒性效应的影响[J].农业环境科学学报,2020,39(6):1185-1195. |
| 纳米二氧化钛对镉胁迫下小白菜毒性效应的影响 |
| Effects of nano titanium dioxide on the toxicity of Chinese cabbage under cadmium stress |
| 投稿时间：2019-12-25 |
| DOI：10.11654/jaes.2019-1422 |
| 中文关键词: 二氧化钛纳米颗粒（TiO2 NPs） Cd 小白菜 植物毒性 氧化损伤 抗氧化酶活性 |
| 英文关键词: TiO2 nanoparticles Cd Chinese cabbage phytotoxicity oxidative damage antioxidant enzyme activity |
| 基金项目:国家重点研发计划项目（2016YFC0503604）；国家自然科学基金青年科学基金项目（41807491） |
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| 中文摘要: |
| 为了探究二氧化钛纳米颗粒（TiO2 NPs）对镉（Cd）胁迫下植物生长生理的影响，以小白菜（Brassica rapa var.glabra）为受试植物，采用水培实验，测定了生物量、丙二醛（MDA）、叶绿素、抗氧化酶活性、超微结构及小白菜根部、地上部中Cd、Ti含量等指标。结果表明：TiO2 NPs增强了Cd对小白菜的生长抑制，株高和干质量分别降低了5.31%和29.79%（P<0.05）；TiO2 NPs使Cd在小白菜根部和地上部的富集水平分别显著增加了64.86%和58.30%（P<0.05）；TiO2 NPs显著加强Cd对小白菜幼苗MDA含量和过氧化氢酶（CAT）、超氧化物歧化酶（SOD）、过氧化物酶（POD）活性的影响；超微结构显示，单一Cd胁迫下小白菜幼苗叶绿体基粒片层模糊且排列紊乱；Cd与TiO2 NPs共存时小白菜根、叶细胞中有大量的TiO2 NPs团聚体，细胞壁折叠、内陷，椭圆叶绿体变圆，类囊体膨胀解体，残存的基粒和基质类囊体更加肿胀、疏松，叶绿素含量显著降低。研究表明，TiO2 NPs作为载体显著促进了小白菜根系对Cd的吸收，并使其转运至地上部，引起膜脂过氧化，破坏幼苗的叶绿体结构和抗氧化系统，增强Cd对小白菜生长的抑制作用。 |
| 英文摘要: |
| To investigate the effects of titanium dioxide nanoparticles(TiO2 NPs)on plant growth and physiology under cadmium(Cd) stress, Chinese cabbage(Brassica rapa var. glabra)was used as a research subject in hydroponic experiments. The biomass, malondialdehyde(MDA), chlorophyll, activities of antioxidant enzymes, ultrastructure, and contents of Cd and Ti in Chinese cabbage roots and shoots were determined. The results showed that with the increase of TiO2 NPs, the growth of Chinese cabbage seedlings was further inhibited under Cd stress, as the height and dry weight of plant decreased by 5.31% and 29.79%(P<0.05), respectively. After TiO2 NPs exposure, the Cd contents in the roots and shoots of the Chinese cabbages increased by 64.86% and 58.30%(P<0.05), respectively. TiO2 NPs exposure significantly enhanced the MDA content, activities of catalase(CAT), superoxide dismutase(SOD), and peroxidase(POD)in Chinese cabbage seedlings under Cd stress. Under a single stress degree of Cd, we found blurred and disorderly arranged chloroplast particles and lamellas. Under TiO2 NPs and Cd co-exposure, a large number of TiO2 NPs aggregated in the cytoplasm of Chinese cabbage root and leaf cells. We also observed that the ultrastructure of Chinese cabbage cells was significantly damaged under TiO2 NPs and Cd co-exposure, including folded and collapsed cell walls, irregular chloroplasts, dilated and disorganized grana thylakoids lamellae, and a significant reduction in chlorophyll content. Our results indicated that TiO2 NPs act as a carrier of Cd bioaccumulation, significantly promoting the absorption of Cd in the roots of Chinese cabbage and transporting them to the ground above. The accumulation of TiO2 NPs and Cd resulted in membrane lipid peroxidation and damages to the chloroplast structure and antioxidant systems of the Chinese cabbage seedlings, which ultimately increased the inhibitory effect of Cd exposure on the growth of Chinese cabbage. |
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