旱柳对土壤纳米二氧化钛与镉单一及共存体系的响应特征OA北大核心CSTPCD

Cadmium(Cd)is a kind of highly toxic heavy metal element which exists in nature for long time.Titani-um dioxide nanomaterials(TiO2 NPs)are a new type of nanomaterial widely used in various fields due to special surface properties,which inevitably enter the environment to coexist with Cd.The coexistence of Cd and TiO2 NPs in soil would affect plant growth.In this study,we conducted morphological,cytological,subcellular observations and physiological and biochemical measurements on Salix matsudana Koidz.seedlings under the single or combined treatments of Cd and TiO2 NPs in soils.The results showed that Cd and TiO2 NPs alone inhibited the growth and de-velopment of S.matsudana,produced peroxide damage,reduced photosynthesis,and altered the distribution of Cd in tissues and subcells.Low concentrations of TiO2 NPs in coexistence with Cd reduced the biotoxicity of Cd by changing the subcellular distribution of Cd,and alleviated the peroxidative damage and photosynthesis inhibition of Cd on S.matsudana.In contrast,high concentrations of TiO2 NPs coexisted with Cd increased the distribution of Cd in organelle fractions,aggravated Cd toxicity to plants,and inhibited plant growth.Therefore,the appropriate con-centration of TiO2 NPs can alleviate the toxic effect of environmental Cd stress on S.matsudana and improve its phytoremediation efficiency.Our findings provide theoretical basis for the application of S.matsudana in phytoreme-diation.